349 results on '"V, Ganesan"'
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2. Low-Temperature Thermoelectric Power Behavior of Nd1 − xGdxCo2: Insights from Impurity and Spin Wave Scattering
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Swati Pandya, L. S. Sharath Chandra, and V. Ganesan
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General Materials Science ,Condensed Matter Physics ,Atomic and Molecular Physics, and Optics - Published
- 2023
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3. Atomic scale microstructural insights of superconducting β-tungsten thin films
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Ananya Chattaraj, Manju Mishra Patidar, V. Ganesan, Sébastien Joulie, Virginie Serin, Alain Claverie, Vijay Kumar, Aloke Kanjilal, SHIV NADAR UNIVERSITY [ Gautam Budh Nagar], Shiv Nadar University, UGC-DAE Consortium for Scientific Research (UGC-DAE ), Bhabha Atomic Research Centre (BARC), Government of India, Department of Atomic Energy-Government of India, Department of Atomic Energy, Matériaux et dispositifs pour l'Electronique et le Magnétisme (CEMES-MEM), Centre d'élaboration de matériaux et d'études structurales (CEMES), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut National des Sciences Appliquées (INSA)-Université de Toulouse (UT)-Institut de Chimie de Toulouse (ICT), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)-Institut National Polytechnique (Toulouse) (Toulouse INP), Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), and Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS) more...
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Mechanics of Materials ,Mechanical Engineering ,General Materials Science ,[PHYS.COND]Physics [physics]/Condensed Matter [cond-mat] ,Condensed Matter Physics - Abstract
International audience; The importance of atomic structure to understand the superconducting β-Tungsten (W) thin films especially their critical transition temperature (Tc) and upper critical magnetic field Hc2(0) is reported. Here, Tc and Hc2(0) for a low thickness (~ 35 nm) film are found to be ~ 3.14 K and 10.72 T, whereas for a comparatively thicker (~ 60 nm) film, these are 1.38 K and 2.34 T, respectively. The β-phase is identified by grazing-incidence X-ray diffraction. The microstructure is probed by transmission electron microscopy, where high-resolution images manifest an improvement in crystallinity of the nanoscale grains in a disordered matrix with increasing film thickness. A drastic change in atomic structure corresponding to two different thicknesses is found to be associated with the change in oxygen concentration. Particularly, the existence of amorphous-W in the presence of β-W is revealed in 35 nm film, which is further supported by ab-initio calculations. Based on the atomic and microstructure, superconducting properties of the β-W films are analyzed and discussed. more...
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- 2022
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4. Structural, magnetic and electrical transport properties of the sol-gel derived La1-xCaxMnO3 (0≤x≤0.3) nanoparticles
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P.V. Jithin, Yugandhar Bitla, Manju Mishra Patidar, V. Ganesan, K.J. Sankaran, and Joji Kurian
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General Materials Science ,Condensed Matter Physics - Published
- 2023
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5. Magnetocaloric Properties of Gd1−xHoxMnO3 Multiferroic Compounds
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Durgesh Singh, A. Srinivas, V. Ganesan, M. Manivel Raja, Jyotirmayee Satapathy, N. Pavan Kumar, and Manju Mishra Patidar
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Materials science ,Thermodynamics ,Atmospheric temperature range ,Condensed Matter Physics ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,010305 fluids & plasmas ,Ion ,Magnetic field ,Phase (matter) ,0103 physical sciences ,Magnetic refrigeration ,Antiferromagnetism ,General Materials Science ,Multiferroics ,Orthorhombic crystal system ,010306 general physics - Abstract
A series of Gd1−xHoxMnO3 (x = 0, 0.1 and 0.2) compounds known to exhibit multiferroic properties has been investigated for their structural, magnetic and magnetocaloric properties. X-ray diffraction analysis confirms the presence of single orthorhombic phase at room temperature in all the compositions. Low temperature magnetocaloric properties of these compounds have been studied through specific heat measurements in the temperature range of 0–80 K under different magnetic fields of 0, 2 and 5 T. These studies also revealed the existence of Mn3+ ordering transition and lock-in transition (Tlock) near 40 K and 20 K, respectively. These compounds displayed antiferromagnetic (AFM) ordering of Gd3+ ions at low temperatures below 10 K. The magnetocaloric effect has been quantified in terms of the magnetic entropy change (ΔS)M and adiabatic temperature change (ΔT)ad in the vicinity of AFM transitions. more...
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- 2020
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6. Soft Ferromagnetic Properties of Half-Metallic Mn2CoAl Heusler Alloy Nanoparticles for Spintronics Applications
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K. Ravichandran, R. K. Kalaiezhily, V. Asvini, G. Saravanan, and V. Ganesan
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010302 applied physics ,Materials science ,Absorption spectroscopy ,Condensed matter physics ,Spintronics ,Ferromagnetic material properties ,Band gap ,Coercivity ,Condensed Matter Physics ,01 natural sciences ,Electronic, Optical and Magnetic Materials ,Amorphous solid ,Ferromagnetism ,0103 physical sciences ,Tauc plot ,010306 general physics - Abstract
The ternary full Heusler alloy Mn2CoAl nanoparticles were synthesized by using co-precipitation technique. The as-prepared sample was observed for amorphous nature and further increased at various annealing temperatures (like 700 °C, 800 °C and 900 °C) in argon gas atmosphere for 5 h. X-ray diffraction studies were performed, and the pattern confirms the formation of Hg2CuTi-type structure of the XA or Xα disorder structure. Williamson-Hall plot (W-H plot) was used to find the uniform deformation model so as to get low value of strain-induced broadening. The presence of Mn2CoAl with the particle size ≈ 50 nm was obtained from high-resolution scanning electron microscopy (HR-SEM), and the elemental analysis study confirms the presence of Mn, Co, and Al. UV-Visible absorption spectrum shows the wide absorption peak at 470 nm and the estimated band gap energy value at Eg = 0.8 eV (from Tauc plot) for 900 °C annealed sample. Synthesized Mn2CoAl nanoparticles induced ferromagnetic behavior due to composition deviation and as a result displayed low coercivity of soft magnetic behavior. Half-metallic ferromagnetic Heusler alloys have a wide range of applications from medical imaging to data storage, and also it has profound spintronics applications. more...
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- 2020
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7. Impurity metallic conduction below the critical concentration of metal-insulator transition in Fe 1−x Co x Si
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M Krishnan and V Ganesan
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General Materials Science ,Condensed Matter Physics - Abstract
Analysis on very detailed measurements of resistivity (ρ) and thermoelectric power (S) of magnetic impurity (Co) substituted iron silicide (FeSi) has been presented in this report. The impurity valence electrons of Co dominate the whole physical properties at low temperatures below 35 K, below the critical concentration x c (≈0.02). The negative thermopower and the positive slope in the resistivity at low temperatures are exciting and show that the system is not entirely insulator below the critical concentration of metal–insulator transition (x c ). So, due to the external impurity electrons, the system’s magnetic ground state could change considerably compared to the parent compound FeSi. This report may help unveil the interesting low-temperature transport properties between x = 0 and x = 0.04 (Fe 1 − x Co x Si). Two band model and variable range hopping model were employed to explain the low-temperature electrical and thermal transport properties. more...
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- 2023
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8. Effect of reentrant spinglass-like states on Schottky Anomaly and exchange bias in polycrystalline Sm0.5Y0.5Fe0.58Mn0.42O3
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S. Raut, S. Chakravarty, H.S. Mohanty, S. Mahapatra, S. Bhardwaj, A.M. Awasthi, B. Kar, K. Singh, M. Chandra, A. Lakhani, V. Ganesan, M. Mishra Patidar, R.K. Sharma, Velaga Srihari, H.K. Poswal, S. Mukherjee, S. Giri, and S. Panigrahi more...
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History ,Polymers and Plastics ,Business and International Management ,Condensed Matter Physics ,Industrial and Manufacturing Engineering ,Electronic, Optical and Magnetic Materials - Published
- 2022
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9. Radiation Enhancement of Superconducting Critical Temperature of Fe-based HTSCs
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Kriti Ranjan Sahu, V. Ganesan, Dirtha Sanyal, Udayan De, Ashish K. Mishra, Thomas Wolf, Argha Banerjee, Department of Physics, Egra S. S. B. College, Egra, Purba Medinipur, West Bengal, India 721429, UGC-DAE CSR, Indore-452001, Madhya Pradhesh India, Variable Energy Cyclotron Centre, 1/AF Bidhannagar, Kolkata 700064, India, and Karlsruhe Institute of Technology, Karlsruhe D-76021, Germany more...
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[PHYS]Physics [physics] ,[SPI]Engineering Sciences [physics] ,Materials science ,Condensed matter physics ,Superconducting critical temperature ,Fe based ,Radiation ,ComputingMilieux_MISCELLANEOUS ,[SPI.MAT]Engineering Sciences [physics]/Materials - Abstract
International audience
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- 2020
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10. Correlation Between Magnetic Ordering and Crossover from Weak Anti-Localization (WAL) to Weak Localization (WL) in Cobalt- and Manganese-Doped Bi0.94Sb0.06 Topological Insulator Nanoparticles
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Sumit Bera, V. Ganesan, R. Venkatesh, Anil K. Mishra, M. Krishnan, Manju Mishra Patidar, and Hasan Afzal
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010302 applied physics ,Materials science ,Spintronics ,Condensed matter physics ,Doping ,Condensed Matter Physics ,01 natural sciences ,Electronic, Optical and Magnetic Materials ,Weak localization ,Condensed Matter::Materials Science ,Ferromagnetism ,Topological insulator ,0103 physical sciences ,Antiferromagnetism ,Condensed Matter::Strongly Correlated Electrons ,Magnetic force microscope ,010306 general physics ,Surface states - Abstract
The discovery of magnetically doped topological insulators (TIs) provides a strong platform for investigating the correlation between long-range ferromagnetic/antiferromagnetic (FM/AFM) ordering and low temperature electron interference phenomena like weak anti-localization (WAL) or weak localization (WL). One such TI material Bi1−xSbx, which has recently been realised as a potential topological material for spintronics, has been studied in the present work. Influence of magnetic doping such as cobalt (Co) and manganese (Mn) in structural, morphological and magneto-transport properties on Bi0.94Sb0.06 nanoparticles has been investigated. The focus was on studying the correlation between magnetic ordering and WAL/WL. In undoped sample for temperatures up to 5K, field dependent magneto resistance (MR) shows a prominent WAL dip around zero field demonstrating the presence of surface states. In both the Co- and Mn-doped samples, the WAL feature is destroyed indicating the absence of time reversal symmetry (TRS) in the system on doping. Interestingly, in the case of 49% manganese (Mn) doping, a clear crossover from WAL to WL has been observed in the MR alongside magnetic ordering and is evident from magnetic force microscopy as well. more...
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- 2020
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11. Survival of Topological Surface States in Cobalt Doped Sb2Te3
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R. Venkatesh, Ashok Kumar Mishra, Sumit Bera, V. Ganesan, M. Krishnan, Manju Mishra Patidar, and Prakash Behera
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010302 applied physics ,Materials science ,Condensed matter physics ,Magnetoresistance ,Solvothermal synthesis ,Doping ,chemistry.chemical_element ,Condensed Matter Physics ,01 natural sciences ,Electronic, Optical and Magnetic Materials ,Weak localization ,chemistry ,Electrical resistivity and conductivity ,Seebeck coefficient ,0103 physical sciences ,010306 general physics ,Cobalt ,Surface states - Abstract
Sb2-xCoxTe3 (x = 0, 0.05, 0.3) nanostructures have been synthesized using microwave-assisted solvothermal synthesis technique. The x = 0 and x = 0.05 samples show a semiconducting-like resistivity with an upturn in the low temperature (T more...
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- 2019
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12. Ferromagnetic ordering in nickel doped BiFeO3 nanostructured thin films
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V. R. Reddy, K. Jeyadheepan, P. M. Razad, K. Mahalakshmi, V. Ganesan, K. Saravanakumar, and R. J. Choudhary
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010302 applied physics ,Materials science ,Doping ,Analytical chemistry ,Coercivity ,Condensed Matter Physics ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,Nanocrystalline material ,Electronic, Optical and Magnetic Materials ,Ferromagnetism ,X-ray photoelectron spectroscopy ,Remanence ,Magnet ,0103 physical sciences ,Electrical and Electronic Engineering ,Thin film - Abstract
The study has made on Ni-doped BiFeO3 (BFO) thin films principally its magnetic properties. BiFe1−xNixO3 (Ni = 0.025, 0.05, 0.075 and 0.10) films were synthesized by the indigenously developed novel hot-wall spray pyrolysis system. It is evidenced from field-emission scanning electron microscopy (FESEM) that Ni doping tremendously modified the shape of the particles from individual rod structure to grouped nanocrystalline grains. M–H curve reveals that Ni doping lead to increase in saturation magnetization and remanent magnetization values of BFO at room temperature (RT) and low temperature (LT). These changes are unveiled due to the structural disorder evidenced from Grazing Incidence X-ray Diffraction (GIXRD) and oxygen vacancy evidenced from X-ray photoelectron spectroscopy (XPS), which are responsible for the magnetic exchange interactions between Fe–O–Fe and Fe–O–Ni. The study of coercivity and blocking temperature with M–H and M–T curves showed that incorporation of Ni decreases the anisotropic energy and coercivity values. These results confirmed that Ni doping modifies the canting structure order which breaks the domains into multi-domains. High retentivity with optimum coercivity makes Ni doped BFO as a good soft magnetic material which finds applications in magnetic data storage devices. more...
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- 2019
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13. Monolayer SiP nanosheets for near and mid-infrared optoelectronic device applications - A DFT approach
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V. Ganesan and V. Vijayakumar
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010302 applied physics ,Materials science ,Dopant ,business.industry ,Band gap ,Ab initio ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Semiconductor ,0103 physical sciences ,Monolayer ,Density of states ,Optoelectronics ,General Materials Science ,Direct and indirect band gaps ,Electrical and Electronic Engineering ,0210 nano-technology ,Electronic band structure ,business - Abstract
The invention of geometrically stable low-dimensional semiconductors along with excellent electronic properties is significant to future optoelectronic devices. Using Ab initio technique, we predict the monolayer silicon phosphide nanosheet (SiP-NS) as a good candidate for near and far-infrared optoelectronic devices due to its excellent dynamical stabilities, more chance for experimental exfoliation, fine-tune the electronic properties with the substitution of proper dopant atoms and prominent anisotropy. The structural and dynamical stability of pristine, Al and B substituted SiP-NS are verified by the cohesive energy and phonon-band-structure. The electronic properties of SiP-NS are demonstrated with the support of the density of states spectrum and energy band structure. The direct energy gap value of pristine SiP-NS is found to be 1.34 eV. The main objective of the proposed research article is to fine tune the electronic characteristics of SiP-NS by the substitution of Al and B atom. Pristine Al and B substituted SiP-NS, with dynamical stability and direct band gap, is a promising material for two dimensional near and mid-infrared optoelectronic devices. more...
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- 2019
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14. Analysis of creep deformation and damage behaviour of 304HCu austenitic stainless steel
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V. Ganesan, K. Laha, Kanhu Charan Sahoo, Parameswaran Padmanabhan, J. Vanaja, Gondesh Varaprasad Reddy, and Sunil Goyal
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010302 applied physics ,Materials science ,Mechanical Engineering ,Metals and Alloys ,02 engineering and technology ,engineering.material ,Condensed Matter Physics ,01 natural sciences ,Finite element method ,020303 mechanical engineering & transports ,Stress range ,0203 mechanical engineering ,Continuum damage mechanics ,Creep ,Mechanics of Materials ,0103 physical sciences ,Materials Chemistry ,Ceramics and Composites ,engineering ,Austenitic stainless steel ,Composite material - Abstract
Creep deformation, damage and rupture behaviour of 304HCu austenitic stainless steel have been studied at temperatures 923, 973 and 1023 K over the stress range 100–240 MPa. The material exhibited ... more...
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- 2019
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15. Adsorption of CO2, H2O, H2S, NH3 and NO2 on germanane nanosheet—A density functional study
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V. Kannan, V. Ganesan, and V. Vijayakumar
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Physical and Theoretical Chemistry ,Condensed Matter Physics ,Biochemistry - Published
- 2022
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16. Spin-liquid behavior of the three-dimensional magnetic system Ba3NiIr2O9 with S=1
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Shashank Kumar Ojha, John W. Freeland, Manju Mishra Patidar, Prithwijit Mandal, V. Ganesan, S. K. Panda, Peter J. Baker, Srimanta Middey, Gangadhar Das, and Siddharth Kumar
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Physics ,Magnetic moment ,Condensed matter physics ,Spins ,Ab initio quantum chemistry methods ,Magnetic lattice ,Condensed Matter::Strongly Correlated Electrons ,Symmetry breaking ,Quantum spin liquid ,Realization (systems) ,Spin-½ - Abstract
The quantum spin liquid (QSL) is an exotic phase of magnetic materials where the spins continue to fluctuate without any symmetry breaking down to zero temperature. Among the handful reports of QSL with spin $S\ensuremath{\ge}$ 1, examples with magnetic ions on a three-dimensional (3D) magnetic lattice are extremely rare since both larger spin and higher dimension tend to suppress quantum fluctuations. In this work, we offer a new strategy to achieve 3D QSL with high spin by utilizing two types of transition metal ions; both are magnetically active but located at crystallographically inequivalent positions. We design a 3D magnetic system ${\mathrm{Ba}}_{3}{\mathrm{NiIr}}_{2}{\mathrm{O}}_{9}$ consisting of interconnected corner-shared ${\mathrm{NiO}}_{6}$ octahedra and face-shared ${\mathrm{Ir}}_{2}{\mathrm{O}}_{9}$ dimer, both having triangular arrangements in a-b plane. X-ray absorption spectroscopy measurements confirm the presence of ${\mathrm{Ni}}^{2+}$ ($S=1)$. Our detailed thermodynamic and magnetic measurements reveal that this compound is a realization of gapless QSL state down to at least 100 mK. Ab initio calculations find a strong magnetic exchange between Ir and Ni sublattices and in-plane antiferromagnetic coupling between the dimers, resulting in dynamically fluctuating magnetic moments. more...
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- 2021
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17. A robust nitridation technique for fabrication of disordered superconducting TiN thin films featuring phase slip events
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Vinay Kaushik, M. P. Saravanan, R. P. Aloysius, V. Ganesan, Sangeeta Sahoo, and Sachin Yadav
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Fabrication ,Materials science ,Annealing (metallurgy) ,Science ,FOS: Physical sciences ,chemistry.chemical_element ,02 engineering and technology ,Substrate (electronics) ,Nitride ,01 natural sciences ,Article ,Superconducting properties and materials ,Superconductivity (cond-mat.supr-con) ,Phase (matter) ,0103 physical sciences ,Condensed-matter physics ,010306 general physics ,Superconductivity ,Condensed Matter - Materials Science ,Resistive touchscreen ,Multidisciplinary ,Condensed matter physics ,Condensed Matter - Superconductivity ,Physics ,Materials Science (cond-mat.mtrl-sci) ,021001 nanoscience & nanotechnology ,chemistry ,Medicine ,0210 nano-technology ,Tin - Abstract
Disorder induced phase slip (PS) events appearing in the current voltage characteristics (IVCs) are reported for two-dimensional TiN thin films produced by a robust substrate mediated nitridation technique. Here, high temperature annealing of Ti/Si3N4 based metal/substrate assembly is the key to produce majority phase TiN accompanied by TiSi2 & elemental Si as minority phases. The method itself introduces different level of disorder intrinsically by tuning the amount of the non-superconducting minority phases that are controlled by annealing temperature (Ta) and the film thickness. The superconducting critical temperature (Tc) strongly depends on Ta and the maximum Tc obtained from the demonstrated technique is about 4.8 K for the thickness range ~ 12 nm and above. Besides, the dynamics of IVCs get modulated by the appearance of intermediated resistive steps for decreased Ta and the steps get more prominent for reduced thickness. Further, the deviation in the temperature dependent critical current (Ic) from the Ginzburg–Landau theoretical limit varies strongly with the thickness. Finally, the Tc, intermediate resistive steps in the IVCs and the depairing current are observed to alter in a similar fashion with Ta and the thickness indicating the robustness of the synthesis process to fabricate disordered nitride-based superconductor. more...
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- 2021
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18. Glassy magnetic state and negative temperature coefficient of resistivity in Mn3+δIn
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Surasree Sadhukhan, Saurav Giri, Subham Majumdar, G. S. Okram, P. Dutta, Sudipta Kanungo, Snehashish Chatterjee, V. Ganesan, Souvik Chatterjee, and Manju Mishra Patidar
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Materials science ,Condensed matter physics ,Magnetic moment ,Fermi energy ,02 engineering and technology ,Electronic structure ,021001 nanoscience & nanotechnology ,01 natural sciences ,Condensed Matter::Materials Science ,Electrical resistivity and conductivity ,Ferrimagnetism ,0103 physical sciences ,Antiferromagnetism ,Condensed Matter::Strongly Correlated Electrons ,010306 general physics ,0210 nano-technology ,Ground state ,Temperature coefficient - Abstract
The complex metallic alloy ${\mathrm{Mn}}_{3}\mathrm{In}$ has recently attracted attention for being a probable candidate for the fully compensated half-metallic ferrimagnet. The compound is associated with a rather unusual negative coefficient of resistivity approximately above the ferrimagnetic, ${T}_{C}=80\phantom{\rule{0.28em}{0ex}}\mathrm{K}$. Our investigation indicates that that the ground state of the alloy is spin-glass like, which possibly coexists with the ferrimagnetic state. The carrier density obtained from the Hall-effect measurement shows a jump below ${T}_{C}$; afterward, it gradually increases with lowering temperature and shows a saturating tendency at the lowest temperature. The electronic structure calculations indicate that, at the Fermi energy, dominant contributions come from minority-spin channels with larger bandwidth. In contrast, very weak but nonzero states arise from the majority-spin channel, and half metallicity can be ruled out. The calculations also found that the antiferromagnetic alignment of Mn spins with nonzero resultant magnetic moment confirms the ferrimagnetic nature consistent with the experimental results. The high-temperature phase with negative temperature coefficient of resistivity can be related to the localization of charge carriers through electron-phonon interactions. more...
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- 2020
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19. Magnetotransport and Berry phase in magnetically doped Bi0.97−xSb0.03 single crystals
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Manju Mishra Patidar, Rajendra S. Dhaka, V. Ganesan, V. K. Maurya, Anita Dhaka, and R. Rawat
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Physics ,Phase transition ,Condensed matter physics ,Magnetoresistance ,Rietveld refinement ,Fermi surface ,Fermi energy ,02 engineering and technology ,Landau quantization ,Type (model theory) ,021001 nanoscience & nanotechnology ,01 natural sciences ,Topological insulator ,0103 physical sciences ,Condensed Matter::Strongly Correlated Electrons ,010306 general physics ,0210 nano-technology - Abstract
We report large magnetoresistance (MR) and Shubnikov-de Haas (SdH) oscillations in single crystals of magnetically (M= Ni and Fe) doped ${\mathrm{M}}_{x}{\mathrm{Bi}}_{0.97\ensuremath{-}x}{\mathrm{Sb}}_{0.03}$ $(x=0, 0.02)$ topological insulators. The $R\overline{3}m$ symmetry and phase have been confirmed by the Rietveld refinement of x-ray diffraction data. Interestingly, a magnetic field induced phase transition from semimetallic to semiconducting type is found with the energy gap around 80 meV at 15 T in the $x=0$ sample. Moreover, we observe linear behavior of MR up to 15 T in transverse mode and SdH oscillations in longitudinal mode where the field direction is parallel with respect to the current and crystal plane. For the parent sample, we found the coherence length ${L}_{\ensuremath{\phi}}=12.7\phantom{\rule{0.28em}{0ex}}\mathrm{nm}$ through the fitting of MR data in transverse mode with modified H-L-N equation. The extracted frequencies of SdH oscillations using the fast Fourier transform method and Landau level (LL) fan diagram are found to be consistent for the parent and Ni doped samples. The determined Fermi surface area is found to be slightly larger in Ni doped as compared to the parent sample possibly due to change in the Fermi energy. The Kohler's plots indicate a single scattering mechanism below 100 K. More importantly, the analysis with the help of the LL fan diagram reveals the nonzero Berry phase ${\ensuremath{\phi}}_{\mathrm{B}}=\ensuremath{-}(1\ifmmode\pm\else\textpm\fi{}0.1)\ensuremath{\pi}$, which demonstrates the nontrivial topological states near the Dirac point in the parent and Ni doped samples. more...
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- 2020
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20. Effect of Calcium doping on Structural and Morphological properties of YBCO Superconductor
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S. B. Shrivastava, Bhavana Singh, V. Ganesan, Nitu Katariya, and L. S. Sharath Chandra
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Superconductivity ,Materials science ,Condensed matter physics ,chemistry ,Doping ,chemistry.chemical_element ,Calcium - Published
- 2020
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21. Magnetic properties of the one-dimensional S=32 Heisenberg antiferromagnetic spin-chain compound Na2Mn3O7
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V. Ganesan, Prabhat Mandal, Bilwadal Bandyopadhyay, A. Midya, Chandragiri Venkatesh, and Krishnan Mahalingam
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Physics ,Condensed matter physics ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,Heat capacity ,Magnetic susceptibility ,Ion ,Spin chain ,Relaxation rate ,Lattice (order) ,0103 physical sciences ,Antiferromagnetism ,Condensed Matter::Strongly Correlated Electrons ,010306 general physics ,0210 nano-technology ,Ground state - Abstract
We have performed magnetic susceptibility $(\ensuremath{\chi})$, heat capacity $({C}_{p})$, and nuclear magnetic resonance (NMR) measurements on the layered compound ${\mathrm{Na}}_{2}{\mathrm{Mn}}_{3}{\mathrm{O}}_{7}$ in which the magnetic ${\mathrm{Mn}}^{4+}$ ions constitute a maple-leaf lattice. At high temperature, $\ensuremath{\chi}$ follows the Curie-Weiss (CW) law with CW temperature as high as 152 K and ${\mathrm{Mn}}^{4+}$ ions are found to be in the high-spin state $(S=\frac{3}{2})$. With decreasing temperature, $\ensuremath{\chi}$ passes through a broad maximum at 115 K and decreases rapidly at low temperature. A similar broad peak appears at around 62 K in the magnetic contribution to heat capacity $({C}_{m})$. The temperature dependence of $\ensuremath{\chi}$ and ${C}_{m}$ are the characteristics of an one-dimensional Heisenberg antiferromagnetic spin chain with a nonmagnetic ground state. The obtained values of spin-gap energy $({\mathrm{\ensuremath{\Delta}}}_{s})$ and nearest-neighbor antiferromagnetic exchange coupling $(J)$ are 28 and 27 K, respectively. There is no evidence of a long-range magnetic ordering down to 2 K in heat capacity data, in agreement with spin-singlet ground state. These observations are further corroborated by $^{23}\mathrm{Na}$ NMR studies through measurements of both the NMR shift and the spin-lattice relaxation rate. more...
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- 2020
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22. Disorder-induced critical exponents near a ferromagnetic quantum critical point in Mn1−xCrxSi
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V. Ganesan, Martin R. Lees, Ashish Kumar Mishra, and S. Shanmukharao Samatham
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Physics ,Condensed matter physics ,02 engineering and technology ,021001 nanoscience & nanotechnology ,01 natural sciences ,Heat capacity ,Magnetic field ,Magnetization ,Ferromagnetism ,Quantum critical point ,0103 physical sciences ,010306 general physics ,0210 nano-technology ,Critical exponent ,Quantum ,Scaling - Abstract
We report the observation of critical behavior in $\mathrm{M}{\mathrm{n}}_{1\ensuremath{-}x}\mathrm{C}{\mathrm{r}}_{x}\mathrm{Si}(0\ensuremath{\le}x\ensuremath{\le}\phantom{\rule{0.16em}{0ex}}1)$ close to a $T=0\phantom{\rule{4pt}{0ex}}\mathrm{K}$ quantum critical point, consistent with the Belitz-Kirkpatrick-Vojta (BKV) theory of disordered metallic ferromagnets. The critical exponents are in good agreement with the theoretical predictions of the BKV theory in the preasymptotic limit. A non-Fermi liquidlike behavior is seen down to 200 mK in the transport and thermodynamic properties around the critical concentration ${x}_{\mathrm{C}}=0.2$. Quantum criticality and self-consistency of the exponents is further confirmed using a scaling analysis of the magnetization and heat capacity data. A recovery to Fermi liquidlike behavior is displayed on moving away from the critical composition, as well as with the application of a magnetic field. more...
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- 2020
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23. Magnetotransport and thermoelectric properties of cobalt doped Bi2Te3 nanostructures
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Sumit Bera, P. Behera, R. Venkatesh, Uday Deshpande, P. Garg, and V. Ganesan
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Mechanics of Materials ,Mechanical Engineering ,General Materials Science ,Condensed Matter Physics - Published
- 2022
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24. Structural, electrical transport and magnetoresistance properties of La0.7Ca0.3MnO3:ZnO nanocomposites
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Vidhi Dhokiya, V.S. Vadgama, D. Venkateshwarlu, R. Venkatesh, A.D. Joshi, Nikesh A. Shah, Hardika Goswami, V. Ganesan, Himanshu Dadhich, Bharavi Hirpara, and P.S. Solanki
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Crystallinity ,Materials science ,Nanocomposite ,Magnetoresistance ,Electrical resistivity and conductivity ,Phase (matter) ,Analytical chemistry ,General Materials Science ,Charge carrier ,Orthorhombic crystal system ,Condensed Matter Physics ,Manganite - Abstract
In the present communication, (1–x) La0.7Ca0.3MnO3 (LCMO) + (x) ZnO (x = 0, 0.10, 0.20) nanocomposites were synthesized by sol–gel method and studied for their charge carrier transport properties. The result of X–ray diffraction (XRD) confirms mixed phases of orthorhombic LCMO with hexagonal ZnO. ZnO admixing does not show any significant change in lattice parameters of LCMO however the peak intensity and crystallinity get suppressed with increase in ZnO content. The samples have been characterized for their electrical transport behaviors using four probe resistivity measurements which confirm that all the studied samples exhibit characteristic insulator to metal transition at temperature TP that decreases with increase in ZnO content. There is a discrepancy in the resistivity values between the LCMO: ZnO nanocomposite samples having the ZnO contents x = 0.10 and 0.20. Variations in the charge carrier transport parameters (i.e. resistivity and TP) with ZnO content have been attributed to the magnetic interactions between manganite and ZnO phases and phase separation scenario in LCMO manganite phase. Various models and mechanisms have been employed to understand the charge conduction processes across the lattices of studied nanocomposites. The largest magnetoresistance (MR) has been seen for x = 0.20 in the LCMO: ZnO nanocomposite which has been attributed to the different distribution possibilities of ZnO within the LCMO manganite lattice of the nanocomposite samples. more...
- Published
- 2022
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25. Visible and near-infrared wavelength-selective dielectric reflectors for light management applications
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V. Ganesan and R.S. Dubey
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010302 applied physics ,Spin coating ,Materials science ,medicine.diagnostic_test ,business.industry ,Infrared ,Near-infrared spectroscopy ,02 engineering and technology ,Dielectric ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Wavelength ,Spectrophotometry ,0103 physical sciences ,medicine ,Optoelectronics ,General Materials Science ,Electrical and Electronic Engineering ,Fourier transform infrared spectroscopy ,0210 nano-technology ,business ,Spectroscopy - Abstract
Wavelength selective reflectors have been widely used in lightemitting diodes, microcavities, waveguides, solar cells and many more. This paper presents the preparation and study of TiO2/SiO2 distributed Bragg reflectors. These multilayer structures were prepared by adopting an easy and cost-effective sol-gel spin coating approach. The prepared samples were examined using field-emission scanning microscopy (FESEM), energy dispersive x-ray (EDS) spectroscopy, ultraviolet–visible (UV–vis) spectrophotometry and Fourier transform infrared (FTIR) spectroscopy. The top surface FESEM studies showed the uniform and homogeneous films while cross-sectional analyses evidenced the periodic structures of TiO2 and SiO2 films. The elemental peaks of Ti, O, and Si were confirmed by EDS investigation. FTIR investigation endorsed the stretching vibration peaks of Ti-O-Ti and Si-O-Si bonds. The reflectance of all samples was studied in accordance with numbers of TiO2/SiO2 stacks and the solution aging. However, the dominant shift of the reflection band from visible to near-infrared wavelength was observed in accordance with the solution aging from 20 to 40 h. more...
- Published
- 2018
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26. Effect of 120 MeV Au9+ ion irradiation on the structure and surface morphology of ZnO/NiO heterojunction
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Rajib Biswal, V. Ganesan, Vasant Sathe, Ram Janay Choudhary, N. C. Mishra, Pankaj Kumar Das, Saif Ahmad Khan, and P. Mallick
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010302 applied physics ,Surface (mathematics) ,Materials science ,Morphology (linguistics) ,Atomic force microscopy ,Non-blocking I/O ,Heterojunction ,02 engineering and technology ,Surfaces and Interfaces ,General Chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Surfaces, Coatings and Films ,Ion ,Stress (mechanics) ,Chemical engineering ,0103 physical sciences ,Materials Chemistry ,Irradiation ,0210 nano-technology - Published
- 2018
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27. Deposition and characterization of spray pyrolysed p-type Cu 2 SnS 3 thin film for potential absorber layer of solar cell
- Author
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P. Sakthi, Sujay Chakravarty, A. Leo Rajesh, S. Thiruvenkadam, V. Ganesan, and S. Prabhakaran
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010302 applied physics ,Materials science ,Band gap ,Analytical chemistry ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Electronic, Optical and Magnetic Materials ,law.invention ,symbols.namesake ,Tetragonal crystal system ,Hall effect ,law ,0103 physical sciences ,Solar cell ,symbols ,Surface roughness ,Electrical and Electronic Engineering ,Thin film ,0210 nano-technology ,Raman spectroscopy ,Layer (electronics) - Abstract
Thin film of ternary Cu2SnS3 (CTS), a potential absorber layer for solar cells was successfully deposited by chemical spray pyrolysis technique. The GIXRD pattern revealed that the film having tetragonal Cu2SnS3 phase with the preferential orientation along (112), (200), (220) and (312) plane and it is further confirmed using Raman spectroscopy by the existence of Raman peak at 320 cm−1. Atomic Force Microscopy (AFM) was used to estimate the surface roughness of 28.8 nm. The absorption coefficient was found to be greater than the order of 105 cm−1 and bandgap of 1.70 eV. Hall effect measurement indicates the p type nature of the film with a hole concentration of 1.03 × 1016cm−3 and a hall mobility of 404 cm2/V. The properties of CTS thin film confirmed suitable to be a potential absorber layer material for photovoltaic applications. more...
- Published
- 2018
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28. High temperature tensile properties of 316LN stainless steel investigated using automated ball indentation technique
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K. Laha, V. Ganesan, and J. Ganesh Kumar
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Materials science ,Structural material ,Mechanical Engineering ,Metals and Alloys ,Uniaxial tension ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,020303 mechanical engineering & transports ,0203 mechanical engineering ,Mechanics of Materials ,Small specimen ,Indentation ,Ultimate tensile strength ,Materials Chemistry ,Ceramics and Composites ,Ball (bearing) ,Composite material ,0210 nano-technology - Abstract
Type 316LN stainless steel (SS) is the principal structural material for the components of sodium cooled fast reactors operating under elevated temperature conditions. In order to assess the degradation in strength of service exposed components using a small specimen testing technique such as automated ball indentation (ABI), it is necessary to carry out prior detailed ABI studies on the virgin material. In this investigation, the tensile behaviour of as-received 316LN SS were investigated at several temperatures in the range 298–973 K using ABI technique. The load-depth of indentation data measured from ABI tests was analyzed using semi-empirical relationships to obtain the tensile properties. The yield stress and the flow curves were determined by correlating ABI results with corresponding uniaxial tensile test results. Trend curve for tensile strength with temperature, as estimated from ABI tests, exhibited a plateau region in the temperature around 823 K, similar to uniaxial tensile tests. The... more...
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- 2018
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29. Effect of Zn/Sn molar ratio on the microstructural and optical properties of Cu 2 Zn 1-x Sn x S 4 thin films prepared by spray pyrolysis technique
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Sujay Chakravarty, Vasant Sathe, V. Ganesan, M.C. Santhosh Kumar, S. Thiruvenkadam, S. Prabhakaran, and A. Leo Rajesh
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010302 applied physics ,Materials science ,Band gap ,Analytical chemistry ,chemistry.chemical_element ,02 engineering and technology ,Zinc ,engineering.material ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Grain size ,Electronic, Optical and Magnetic Materials ,chemistry.chemical_compound ,Crystallinity ,chemistry ,0103 physical sciences ,engineering ,CZTS ,Kesterite ,Electrical and Electronic Engineering ,Thin film ,0210 nano-technology ,Tin - Abstract
Quaternary kesterite Cu2ZnSnS4 (CZTS) compound is one of the most promising semiconductor materials consisting of abundant and eco-friendly elements for absorption layer in thin film solar cells. The effect of Zn/Sn ratio on Cu2Zn1-xSnxS4 (0 ≤ x ≤ 1) thin films were studied by deposited by varying molar volumes in the precursor solution of zinc and tin was carried out in proportion of (1-x) and x respectively onto soda lime glass substrates kept at 573 K by using chemical spray pyrolysis technique. The GIXRD pattern revealed that the films having composites of Cu2ZnSnS4, Cu2SnS3, Sn2S3, CuS and ZnS phases. The crystallinity and grain size were found to increase by increasing the x value and the preferential orientation along (103), (112), (108) and (111) direction corresponding to CZTS, Cu2SnS3, CuS, and ZnS phases respectively. Micro-Raman spectra exposed a prominent peak at 332 cm−1 corresponding to the CZTS phase. Atomic force microscopy was employed to study the grain size and roughness of the deposited thin films. The optical band gap was found to lie between 1.45 and 2.25 eV and average optical absorption coefficient was found to be greater than 105 cm−1. Hall measurements exhibited that all the deposited Cu2Zn1-xSnxS4 films were p type and the resistivity lies between 10.9 × 10−2 Ωcm and 149.6 × 10−2 Ωcm . more...
- Published
- 2018
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30. The effect of titanium dioxide nano-filler on the conductivity, morphology and thermal stability of poly(methyl methacrylate)—poly(styrene-co-acrylonitrile) based composite solid polymer electrolytes
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K. K. Mothilal, S. Selvasekarapandian, S. V. Ganesan, and T. K. Ganesan
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Materials science ,chemistry.chemical_element ,02 engineering and technology ,Conductivity ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Poly(methyl methacrylate) ,Atomic and Molecular Physics, and Optics ,0104 chemical sciences ,Electronic, Optical and Magnetic Materials ,chemistry.chemical_compound ,chemistry ,Chemical engineering ,visual_art ,Propylene carbonate ,visual_art.visual_art_medium ,Ionic conductivity ,Lithium ,Polymer blend ,Electrical and Electronic Engineering ,0210 nano-technology ,Glass transition ,Ethylene carbonate - Abstract
The composite solid polymer electrolyte (CSPE) samples, comprising of poly(methylmethacrylate) (PMMA)/poly(styrene-co-acrylonitrile) (SAN)/ethylene carbonate (EC)/propylene carbonate (PC)/lithium trifluoromethanesulfonate (LiCF3SO3)/anatase-TiO2 as nano-filler (0, 5, 6, 7, 8 and 9 wt% for samples T0, T1, T2, T3, T4 and T5 respectively) were prepared by solution casting technique. Fourier transform infrared (FT-IR) spectral studies indicate the interaction of PMMA and plasticizers (EC, PC) with Lithium ion and nano-filler TiO2 in samples. From AC impedance studies ionic conductivity, dielectric constant increase with increase in the concentration of nano-filler TiO2 up to 9 wt%. The sample T5 shows lowest activation energy (Ea) of 0.14 eV, very short relaxation time (τ) of 1.49 × 10−7 s and exhibits maximum ionic conductivity of 1.05 × 10−4 S cm−1 at room temperature. The conductivity-temperature dependence studies showed that the conductivity of all samples depict Arrhenius behaviour suggesting ion-hopping mechanism. Dielectric studies reveal ion conducting nature of CSPE samples. Thermogravimetric analysis indicate the thermal stability of CSPE sample T5 up to 333 °C with maximum degradation at 388 °C. DSC studies reveal absence of glass transition temperature (Tg) of atactic component of PMMA in CSPE sample T5 indicating amorphous nature. X-ray diffraction patterns shows shift in the position of peaks confirming the complex formation of the PMMA-SAN-EC-PC-LiCF3SO3-TiO2 system. SEM analysis indicates that the presence of lithium salt and filler TiO2 on polymer host does not lead to heterogenous polymer blend thus retaining its amorphous nature. more...
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- 2018
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31. Studies on magneto conductance of nickel substituted FeSi
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M. Krishnan, Mohan Gangrade, Sankararao Yadam, Ashish Kumar Mishra, R. Venkatesh, Durgesh Singh, and V. Ganesan
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Materials science ,Magnetic moment ,Condensed matter physics ,Kondo insulator ,Doping ,chemistry.chemical_element ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Electronic, Optical and Magnetic Materials ,Weak localization ,Condensed Matter::Materials Science ,Nickel ,chemistry ,Impurity ,Electrical resistivity and conductivity ,Seebeck coefficient ,0103 physical sciences ,Condensed Matter::Strongly Correlated Electrons ,010306 general physics ,0210 nano-technology - Abstract
Structural and electrical transport properties of Nickel (Ni) doped FeSi at low temperatures in the presence of zero and high magnetic fields are investigated systematically and reported. FeSi is a material known for its high thermoelectric power. Metal-Insulator Transition in FeSi is always an exotic one with different ground states depending upon the substituent. Changes in Magneto Resistance (MR) at low temperatures are explained by invoking an interplay between Weak Localization (WL) and enhanced Electron-Electron Interaction (EEI) that evolved upon varying the nickel concentrations. Competing interactions between WL and EEI along with Kondo hybridization scenario may classify this system into an exotic one among doped semiconductors. Temperature dependent zero field resistivity is analyzed in the light of various scattering mechanism in different doping regimes at low temperatures. Different crossover regimes are explained by invoking carriers and magnetic moments induced by the Ni impurity in an otherwise non-magnetic Kondo Insulator (KI). more...
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- 2018
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32. Spin fluctuations in Cr doped MnSi
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Mohan Gangrade, Ashish Kumar Mishra, R. Venkatesh, Durgesh Singh, V. Ganesan, S. Shanmukharao Samatham, and M. Krishnan
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010302 applied physics ,Physics ,Magnetic transition temperature ,Specific heat ,Field (physics) ,Condensed matter physics ,Magnetoresistance ,Cr doped ,Condensed Matter Physics ,01 natural sciences ,Electronic, Optical and Magnetic Materials ,Magnetic field ,Electrical resistivity and conductivity ,0103 physical sciences ,010306 general physics ,Spin-½ - Abstract
Transport and calorimetric properties of Mn 1−x Cr x Si ( x = 0.025) down to 2 K and magnetic fields up to 13 T are reported. Electrical resistivity in zero field as well as in magnetic fields, below a magnetic transition temperature, T c = 23.6 K could be described using a T 2 term with large coefficient, invoking the role of spin fluctuations. Sommerfeld coefficient ‘γ’ of specific heat is an enhanced one as compared to the pure MnSi. Negative magnetoresistance (35% at 13 T) with maximum at T c and a decrease in coefficient of T 2 term in resistivity suggests the suppression of spin fluctuations in high magnetic fields. This is further supported by negative magneto-specific heat in the vicinity of T c coupled with a decrement in the Sommerfeld coefficient ‘γ’ of specific heat under a field of 10 T. Kadowaki-Woods ratio places the system close to other systems showing strong spin fluctuations. more...
- Published
- 2018
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33. Superconducting and normal state properties of quasi-one-dimensional Nb2Pd(S0.9Te0.1)5 system
- Author
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D. Venkateshwarlu, R. Venkatesh, Vinay Kaushik, and V. Ganesan
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Superconductivity ,Materials science ,Condensed matter physics ,State (functional analysis) ,Condensed Matter Physics ,Heat capacity ,Electronic, Optical and Magnetic Materials ,Vortex ,Inorganic Chemistry ,Condensed Matter::Superconductivity ,Seebeck coefficient ,Materials Chemistry ,Ceramics and Composites ,Jump ,Grain boundary ,Physical and Theoretical Chemistry ,Scaling - Abstract
A comprehensive study of superconducting and normal state properties of Nb2Pd(S0.9Te0.1)5 system which consists of solid chunks embedded with mesh of fibers has been presented here. Below the superconducting transition temperature, in different iso-magnetic fields, the motion of vortices in mixed state has been analyzed using thermally activated flux flow (TAFF) model and the obtained thermal activation energy (TAE) follows Kramer’s scaling which suggests the dominance of mechanism similar to grain boundary pinning in these fibers. Bulk nature of superconductivity is clearly seen in specific heat data, however with a jump of ∼0.97, less than the BCS estimate, places these fibers in weak coupling strength limit. Low temperature electronic heat capacity down to 2 K point towards a fully gapped s-wave superconductivity in these fibers. Moreover, normal state study using thermoelectric power data suggests a hole dominated transport in this system. more...
- Published
- 2022
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34. Semiconducting nature and magnetoresistance behaviour of ZnO / La0.3Ca0.7MnO3 / SrTiO3 heterostructures
- Author
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Nikesh A. Shah, P.S. Solanki, Bhargav Rajyaguru, Sukriti Hans, Mukesh Ranjan, R. Venkatesh, Himanshu Dadhich, V. Ganesan, and D. Venkateshwarlu
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Diffraction ,Materials science ,Condensed matter physics ,Magnetoresistance ,Mechanical Engineering ,Field dependence ,Heterojunction ,Condensed Matter Physics ,Manganite ,Magnetic field ,Mechanics of Materials ,Electrical resistivity and conductivity ,General Materials Science ,Charge carrier - Abstract
In this report, ZnO /La0.3Ca0.7MnO3 /SrTiO3 (ZnO /LCMO /STO) heterostructures, with various thicknesses of LCMO, were grown successfully using chemical solution deposition (CSD) method. X–ray diffraction (XRD) measurement confirms the presence of LCMO and ZnO phases only without any other unwanted phases. To understand the charge conduction mechanisms across ZnO /LCMO interface as well as for LCMO manganite thin layer, temperature dependent resistivity measurements have been investigated under different applied magnetic fields. The measured ρ (T) data of all the heterostructures in current perpendicular to plane (CPP; for ZnO /LCMO interface studies) mode and current in plane (CIP; for LCMO thin layer studies) mode show the semiconducting behaviour throughout the temperature and magnetic field range studied. The semiconducting state of all the heterostructures have been studied using Mott type variable range hopping (VRH) mechanism to understand the field dependence of charge carrier localization length. Observed negative magnetoresistance (MR) has been discussed in detail with its dependence on applied magnetic field, temperature and manganite layer thickness. more...
- Published
- 2021
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35. Significant enhancement in thermoelectric power with Iso-electronic doping in c-axis oriented MoTe2 nano bulk sheets
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Hasan Afzal, R. Venkatesh, and V. Ganesan
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Materials science ,Condensed matter physics ,Mechanical Engineering ,Doping ,chemistry.chemical_element ,Condensed Matter Physics ,Thermoelectric materials ,chemistry ,Mechanics of Materials ,Electrical resistivity and conductivity ,Impurity ,Seebeck coefficient ,Figure of merit ,General Materials Science ,Tellurium ,Temperature coefficient - Abstract
The search for techniques to enhance thermoelectric power as well as figure of merit is indispensable in the development of thermoelectric materials. In this work, iso-electronic substitution of Tellurium with 9% Sulfur in MoTe2 nano-bulk sheets showed an 88% room temperature enhancement in thermopower combined with a 13% increase in power factor with a negative temperature coefficient of resistivity below 80 K. To correlate the results, a two-band model was successfully applied to temperature variation of both thermopower and resistivity. The results ascribe the thermopower enhancement to the formation of a narrow sulfur impurity band, which causes, a considerable percentage of the holes to pop-up to the valence band maximum and get localized around the S2-cores, resulting in a sharp depletion in hole density available for transport. The application of the two-carrier model to the field dependent magneto resistance, supports the above proposed reduction in hole density. Our results shed light on doping induced thermopower tuning, leading to more efficient thermo-electrics. more...
- Published
- 2021
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36. Transport properties, charge conduction mechanism and magnetic behavior of La0.3Ca0.7MnO3:ZnO Nanocomposites
- Author
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R. Venkatesh, Himanshu Dadhich, D. Venkateshwarlu, Vidhi Dhokiya, A.D. Joshi, Neeta A. Bhammar, P.S. Solanki, Bhagyashree Udeshi, Nikesh A. Shah, Keval Gadani, and V. Ganesan
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Materials science ,Magnetoresistance ,Condensed matter physics ,Mechanical Engineering ,Condensed Matter Physics ,Manganite ,Magnetic field ,Magnetization ,Mechanics of Materials ,Electrical resistivity and conductivity ,General Materials Science ,Charge carrier ,Grain boundary ,Crystallite - Abstract
Nanocomposites consist of ZnO and La0.3Ca0.7MnO3 (LCMO) nanoparticles, prepared by cost effective sol–gel method, have been studied for their transport and magnetoresistance (MR) behaviors. Different ZnO nanoparticles contents (weight ratio) were mixed with LCMO nanostructured manganite to understand the possible interactions between ZnO and LCMO nanoparticles. X–ray diffraction (XRD) measurement was performed for all composites and structural quality was verified by performing Rietveld refinements. Variation in an average crystallite size for LCMO and ZnO nanoparticles in different composites has been discussed. Temperature dependent resistivity measurements under different applied magnetic fields suggest the semiconducting nature of all nanocomposites under all applied magnetic fields. Mott type variable range hopping (VRH) mechanism has been employed to understand the dependence of charge carrier localization in LCMO nanostructured manganite lattice on the applied magnetic field and ZnO nanoparticles content within the nanocomposites. Observed MR behavior has been understood under the influence of temperature and ZnO nanoparticles content in the context of spin polarized tunneling (SPT) and magnetic field induced improved conduction across the manganite lattice. Grain and grain boundary contributions to the MR behavior have been explained by using theoretical model fits to obtained MR data at different temperatures for all studied LCMO:ZnO nanocomposites. Magnetic nature of studied LCMO:ZnO nanocomposites has been understood by performing zero field cooled (ZFC) and field cooled (FC) measurement protocols based magnetization and magnetic isotherms measurements that confirm the coexisting magnetic phase in all studied nanocomposites. Magnetic nature has been understood on the basis of weakening of zener double exchange (ZDE) mechanism within the magnetic lattice of LCMO manganite and magnetic contribution from the free charge carriers within the ZnO clusters. more...
- Published
- 2021
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37. Evolution of surface topography and optical band gap of ZnO film deposited on NiO/Si(100)
- Author
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P. K. Das, Ram Janay Choudhary, R. Biswal, P. Mallick, and V. Ganesan
- Subjects
010302 applied physics ,Surface (mathematics) ,Materials science ,business.industry ,Band gap ,Non-blocking I/O ,02 engineering and technology ,Surfaces and Interfaces ,General Chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Surfaces, Coatings and Films ,0103 physical sciences ,Materials Chemistry ,Optoelectronics ,0210 nano-technology ,business - Published
- 2017
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38. Reflectance modulation using SiO2/TiO2 multilayer structures prepared by sol-gel spin coating process for optical applications
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V. Ganesan and R.S. Dubey
- Subjects
Spin coating ,Fabrication ,Materials science ,business.industry ,02 engineering and technology ,Molding (process) ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Electromagnetic radiation ,Grain size ,0104 chemical sciences ,Optics ,Surface roughness ,Optoelectronics ,General Materials Science ,Electrical and Electronic Engineering ,0210 nano-technology ,business ,Refractive index ,Sol-gel - Abstract
Passive devices made of SiO 2 /TiO 2 bilayers have been demanded for the molding of electromagnetic waves in optical waveguides, microcavities, solar cells, sensors and so on. Here, we present the fabrication and characterization of SiO 2 /TiO 2 multilayer structures as reflectors. The refractive indices were found to be 1.43 & 2.0 with thicknesses 230 & 70 nm corresponding to the SiO 2 and TiO 2 films respectively. AFM surface topography study showed little bit large surface roughness of the TiO 2 as compared to SiO 2 film due to its large grain size. The corresponding reflectance enhancement was noticed with the increased number of bilayers of SiO 2 /TiO 2 films. Furthermore, six alternate layers of SiO 2 /TiO 2 demonstrated the as much as 78% reflectance in the near-infrared wavelength range. more...
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- 2017
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39. Surface characterization and gas sensing performance of yttrium doped TiO2 nanofilms prepared by automated nebulizer spray pyrolysis (ANSP)
- Author
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V. Ganesan, P. Elango, and V. Gopala Krishnan
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Anatase ,Materials science ,Band gap ,Doping ,Analytical chemistry ,chemistry.chemical_element ,02 engineering and technology ,Yttrium ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,0104 chemical sciences ,Electronic, Optical and Magnetic Materials ,Tetragonal crystal system ,Absorption edge ,X-ray photoelectron spectroscopy ,chemistry ,Crystallite ,Electrical and Electronic Engineering ,0210 nano-technology - Abstract
YxTi1−xO2 nanofilms were deposited on glass substrate at 500 °C by automated nebulizer spray pyrolysis route. The influence of yttrium concentration on XRD shows the stabilized anatase tetragonal polycrystalline nature and *(222), *(400) plane orientation of Y2O3 were revealed by Y = 10%. An XPS spectrum reveals the primary elements such as O 1s, Ti 2p, Y 3d, Ti 3p and C 1s with a binding energy respectively. The morphological study of FESEM shows the modification from granular spherical to honeycomb structure based on yttrium concentration. Optical study shows the blue shift of sharp absorption edge with increased band gap values (E g = 3.20 eV–3.78 eV) is depends upon Y concentration. Notably, gas sensing performance of YxTi1−xO2 shows the highest sensitivity response to Y = 10% (Y0.10Ti9.90O2) of NH3 at 150 °C with 300 ppm gas concentration and all the films exhibits better sensitivity response in order to NH3 > C2H6O > C3H6O> CH4O > C3H8O. more...
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- 2017
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40. Role of carrier concentration in swift heavy ion irradiation induced surface modifications
- Author
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Sushant Gupta, V. Ganesan, Indra Sulania, and B. Das
- Subjects
Condensed Matter - Materials Science ,Materials science ,Analytical chemistry ,Materials Science (cond-mat.mtrl-sci) ,FOS: Physical sciences ,02 engineering and technology ,Surfaces and Interfaces ,Conductivity ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Threshold energy ,Microstructure ,01 natural sciences ,Crystallographic defect ,Surfaces, Coatings and Films ,Ion ,Swift heavy ion ,0103 physical sciences ,Materials Chemistry ,Irradiation ,Thin film ,010306 general physics ,0210 nano-technology - Abstract
Highly conducting $SnO_{2}$ thin films were prepared by chemical spray pyrolysis technique. One set of as-deposited films were annealed in air for 2 h at 850$^{o}$C. These as-deposited and annealed films were irradiated using $Au^{9+}$ ions with energy of 120 MeV at different fluences ranging from $1\times10^{11}$ to $3\times10^{13}$ $ions/cm^{2}$. Electrical measurement shows that as-deposited $SnO_{2}$ films are in conducting state with n = $3.164 \times 10^{20}$ $cm^{-3}$ and annealed $SnO_{2}$ films are in insulating state. The amorphized latent tracks are created only above a certain threshold value of $S_{e}$, which directly depends on the free electron concentration (n). The electronic energy loss ($S_{e}$) of 120 MeV $Au^{9+}$ ions in $SnO_{2}$ is greater than the threshold energy loss ($S_{eth}$) required for the latent track formation in annealed $SnO_{2}$ thin film, but is less than $S_{eth}$ required for as-deposited $SnO_{2}$ film. Therefore, the latent tracks are formed in the annealed $SnO_{2}$ film and not in the as-deposited $SnO_{2}$ film. Thermal spike model is used for the calculation of threshold energy loss and radius of melted zone. The possible mechanism of the structural changes and surface microstructure evolutions is briefly discussed in the light of ion's energy relaxation processes and target's conductivity. The atomic force microscopy (AFM) study of films shows that the morphologies of irradiated films are linked with carrier concentration of target materials., 13 pages, 5 figures, 3 tables, 79 references. arXiv admin note: substantial text overlap with arXiv:1512.06119 more...
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- 2017
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41. Growth, mechanism and properties of TiO2 nanorods embedded nanopillar: Evidence of lattice orientation effect
- Author
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K. Mahalakshmi, V. Ganesan, Manju Mishra Patidar, P. M. Razad, V.R. Sreelakshmi, K. Saravanakumar, K. Jeyadheepan, G. Marimuthu, M. Jithin, and V.R. Reddy
- Subjects
010302 applied physics ,Materials science ,Nucleation ,Nanotechnology ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Tin oxide ,01 natural sciences ,Nanomaterials ,Crystal ,chemistry.chemical_compound ,Tetragonal crystal system ,chemistry ,0103 physical sciences ,Titanium dioxide ,General Materials Science ,Nanorod ,Electrical and Electronic Engineering ,0210 nano-technology ,Nanopillar - Abstract
Worldwide researchers and scientists are taking efforts to develop novel structured highly crystallized nanomaterials to fabricate devices for various applications. In this report, we demonstrate the synthesis of self-originated single phase Titanium dioxide (TiO 2 ) nanorods embedded nanopillar on nanotent grain under simple hydrothermal method. Synthesized TiO 2 nanopillars are in single crystalline tetragonal crystal structure with rutile phase. Understanding the fundamental crystal nucleation and growth mechanism is more critical in the semiconducting oxide thin films with controlled size and morphological features. The growth mechanism of TiO 2 nanopillars on the surface of Fluorine doped Tin Oxide (FTO) substrate is explained in support of FESEM and AFM images. The optical emission properties are studied with photoluminescence spectroscopy. more...
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- 2017
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42. New insights to damage initiation during creep deformation of stainless steel weld joints
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K. Laha, V.D. Vijayanand, and V. Ganesan
- Subjects
010302 applied physics ,Heat-affected zone ,Materials science ,Mechanical Engineering ,Metallurgy ,02 engineering and technology ,Welding ,engineering.material ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,law.invention ,Stress (mechanics) ,Creep ,Mechanics of Materials ,law ,Cavitation ,0103 physical sciences ,engineering ,General Materials Science ,Austenitic stainless steel ,0210 nano-technology ,Joint (geology) ,Electron backscatter diffraction - Abstract
A systematic investigation has been carried out to asses the creep cavitation behaviour in austenitic stainless steel fusion zone by performing detailed microstructural and finite element analysis. Metallographic observations of the failed cross-weld joint specimens reveal that the cavities nucleated in the near-crown region and propagated towards the near-root region. Similar pattern of nucleation and growth of cavities was observed in weld joint tested at a different stress level. The preferential nucleation of creep cavities in the near-crown region of the weld joint can be attributed to both micro and macro inhomogeneities in the weld joint. The micro-inhomogeneity in the fusion zone, which could be characterized using electron backscatter diffraction studies, is a result of variations in morphology and formation of thermo-mechanically treated region across the weld pass interface. The considerable strength variation between the heat affected zone, base metal and fusion zone resulted in macro-inhomogeneity in the weld joint and introduced significant stress gradients which could be illustrated using finite element analysis. Both micro and macro-inhomogeneities have a synergistic role in determining the damage initiation location in multi-pass stainless steel weld joints subjected to creep. more...
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- 2017
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43. Low temperature transport anomaly in Cr substituted (La0.67Sr0.33)MnO3 manganites
- Author
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V. Ganesan, Tejas M. Tank, S. Shanmukharao Samatham, D. S. Rana, Sankar P. Sanyal, C. M. Thaker, Sarmistha Das, and Vilas Shelke
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Colossal magnetoresistance ,Materials science ,Condensed matter physics ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Manganite ,01 natural sciences ,Electronic, Optical and Magnetic Materials ,Magnetic field ,Condensed Matter::Materials Science ,Paramagnetism ,Ferromagnetism ,Electrical resistivity and conductivity ,0103 physical sciences ,Antiferromagnetism ,Condensed Matter::Strongly Correlated Electrons ,Crystallite ,010306 general physics ,0210 nano-technology - Abstract
The structural, electrical, and magnetic properties of La0.67Sr0.33Mn1−xCrxO3 (0 ≤ x ≤ 0.10) manganites have been studied by substitution of antiferromagnetic trivalent Cr ion at Mn-site. Systematic efforts have been carried out to understand the electrical resistivity behavior in the ferromagnetic metallic and paramagnetic semi-conducting phases of Cr substituted La0.67Sr0.33Mn1−xCrxO3 manganites. Polycrystalline samples show a resistivity minimum at a temperature (Tmin) of more...
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- 2017
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44. Thermopower study of polycrystalline Fe intercalated TiSe2
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V. Ganesan, R. Venkatesh, Vinay Kaushik, and Prakash Behera
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Materials science ,Condensed matter physics ,Electrical resistivity and conductivity ,Seebeck coefficient ,Transition temperature ,Crystallite ,Activation energy ,Diffusion (business) ,Scaling ,Charge density wave - Abstract
In this article, thermopower study of the polycrystalline TiSe2 and its Fe intercalated TiSe2 has been analyzed in detail. TiSe2 is two dimensional material which formed in hexagonal crystal structure having space group p3m1(164). Temperature dependent resistivity shows a considerable shift in Charge Density Wave (CDW) transition temperature towards low temperature with vanishing CDW peak intensity. The thermopower data shows peak or dip indicating the existence of CDW hybridization and this is in line with the electrical transport data. A scaling has been done in thermopower data by normalization which can be understood in terms of variation of hybridization across the CDW transition. Further, the temperature dependent thermopower data is well fitted using Nordheim-Gorter rule by Two Band Model (TBM). The results of the fittings indicate a drastic decrease of activation energy upon Fe intercalation in TiSe2 in semiconducting counterpart. Moreover, Diffusion thermopower corresponding to the metallic part is systematic as far as carrier compensation is concerned. more...
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- 2020
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45. Oxygen Vacancy-Induced Topological Hall effect in a Nonmagnetic Band Insulator
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Prithwijit Mandal, Shashank Kumar Ojha, V. Ganesan, R. Venkatesh, Ranjan Kumar Patel, Manish Jain, Srimanta Middey, Manju Mishra Patidar, Sanat Kumar Gogoi, and Siddharth Kumar
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Physics ,Condensed Matter - Materials Science ,Nuclear and High Energy Physics ,Magnetic moment ,Magnetoresistance ,Skyrmion ,Materials Science (cond-mat.mtrl-sci) ,FOS: Physical sciences ,Statistical and Nonlinear Physics ,Spin–orbit interaction ,Electron ,Condensed Matter Physics ,Polaron ,Topology ,Electronic, Optical and Magnetic Materials ,Computational Theory and Mathematics ,Hall effect ,Vacancy defect ,Electrical and Electronic Engineering ,Mathematical Physics - Abstract
The discovery of skyrmions has sparked tremendous interests about topologically nontrivial spin textures in recent times. The signature of noncoplanar nature of magnetic moments can be observed as topological Hall effect (THE) in electrical measurement. Realization of such nontrivial spin textures in new materials and through new routes is an ongoing endeavour due to their huge potential for future ultra-dense low-power memory applications. In this work, we report oxygen vacancy (OV) induced THE and anomalous Hall effect (AHE) in a 5$d^0$ system KTaO$_3$. The observation of weak antilocalization behavior and THE in the same temperature range strongly implies the crucial role of spin-orbit coupling (SOC) behind the origin of THE. Ab initio calculations reveal the formation of the magnetic moment on Ta atoms around the OV and Rashba-type spin texturing of conduction electrons. In the presence of Rashba SOC, the local moments around vacancy can form bound magnetic polarons (BMP) with noncollinear spin texture, resulting THE. Scaling analysis between transverse and longitudinal resistance establishes skew scattering driven AHE in present case. Our study opens a route to realize topological phenomena through defect engineering., Comment: Published in Advanced Quantum Technology more...
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- 2020
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46. Influence of carrier concentration and mobility tuned magneto resistance of Bi1−xSbx nanocrystals
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R. Venkatesh, Hasan Afzal, and V. Ganesan
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Electron mobility ,Materials science ,Condensed matter physics ,Nanocrystal ,Topological insulator ,Doping ,Solvothermal synthesis ,Electron ,Magneto ,Magnetic field - Abstract
In the present work, influence of Sb doping on magneto transport properties of the topological insulator Bi1−xSbx in its nano crystalline form, prepared by microwave assisted solvothermal synthesis, is investigated. At a fixed temperature of 4K, for x=0.06, a positive linear magneto resistance (PLMR) at low magnetic fields was observed, which transforms towards a parabolic classical MR curve with a further increase in Sb molar ratio x. The slope of MR was found to increase with x, the deviation from linearity was found to be attributable to a monotonic decrease in average carrier mobility as well as a systematic increase in the carrier concentration (electron- hole) asymmetry ratio. This elucidates on a possible mechanism for tuning of MR by varying carrier concentration as well as mobility and hence is likely to be instrumental in development of MR dependent devices. more...
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- 2020
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47. Enhancement of the upper critical field (HC2) in Nb2Pd(S0.9Te0.1)5 superconducting fibers
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Vinay Kaushik, D. Venkateshwarlu, R. Venkatesh, and V. Ganesan
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Superconductivity ,Materials science ,Condensed matter physics ,Crystallite ,Atmospheric temperature range ,Anomaly (physics) ,Power law ,Critical field ,Excitation ,Electron localization function - Abstract
Here, we report the synthesis and characterization of the Nb2Pd(S0.9Te0.1)5 superconductor. The resultant polycrystalline sample is consists of solid chunks along with mesh of fibers which are grown in thin long rod shapes having length in several millimeters with cross-sectional area around 5x3 µm2. The normal state of this superconductor behaves abnormally compared to its parent compound (Nb2PdS5) which is shown here. In high temperature regime (T > 125K) it follows the power law which is completely different from its parent analog which shows metallicity (linear behavior) in high temperature range. Below this temperature region a broad peak appears centered around T* ≈ 62K, the origin of this anomaly is unknown right now, followed by a dip which is centered around T’ ≈ 23K which may be some sort of electron localization or some gap like excitation which preceding the superconducting transition having onset at Tc (onset)≈ 6.7K. The upper critical field value Hc2(0) = 52.24T enhances in these superconducting fibers. Aslamazov-Larkin (AL) theory shows three significant (3D, 1D and short-wave (SW)) fluctuation regimes in these superconducting fibers. more...
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- 2020
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48. Magnetotransport and thermal properties of microwave synthesized nanostructured Bi2Te3
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Sumit Bera, R. Venkatesh, Prakash Behera, and V. Ganesan
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010302 applied physics ,Materials science ,Condensed matter physics ,Magnetoresistance ,Dephasing ,General Physics and Astronomy ,02 engineering and technology ,Conductivity ,021001 nanoscience & nanotechnology ,01 natural sciences ,Heat capacity ,Degenerate semiconductor ,Magnetic field ,Electrical resistivity and conductivity ,Seebeck coefficient ,0103 physical sciences ,0210 nano-technology - Abstract
Magnetotransport and thermal properties of microwave-synthesized nanostructured Bi2Te3, a well-known material of topological interest, have been studied in detail. Temperature-dependent resistivity shows a disordered metal-like behavior at high temperature with unsaturated ln(T)-dependent upturns at low temperature manifesting localization tendency. The slopes (κ) of the normalized conductivity (Δσ) vs ln(T) curves change sharply with magnetic fields upto 1 T and then saturate at a certain higher field (Bϕ), which is an indication of a combined electron–electron interaction and quantum interference effect (QIE) dominated transport. A noteworthy result is a crossover from positive to negative Coulomb screening factor (F) in Bi2Te3. Low-field (H ≤ 1 T) magnetoconductivity at low temperature follows a 2D Hikami–Larkin–Nagaoka equation, thereby revealing the QIE and associated dephasing nature of the electronic states at high temperatures. High-field (14 T) magnetoresistance (MR) at 2 K shows interesting features like low-field weak antilocalization, possibly a defect-induced negative MR that vanishes after post-annealing treatment, and a high field parabolic character in place. The Seebeck coefficient (S) is negative and varies quasilinearly with a slight but notable slope change at intermediate temperatures. Heat capacity measurements are in line with a narrow gap degenerate semiconductor with a low θD of 140 K. A combined analysis of heat capacity and thermopower reveals the localization of carriers at low temperatures and is in line with transport data. more...
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- 2021
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49. Magnetic and transport properties of inverse Heusler compound Cr2CoAl
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Sangam Banerjee, Amrita Datta, T. V. Chandrasekhar Rao, M. Modak, Pralay Paul, V. Ganesan, and Manju Mishra Patidar
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010302 applied physics ,Materials science ,Magnetic moment ,Condensed matter physics ,Magnetism ,02 engineering and technology ,engineering.material ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Heusler compound ,01 natural sciences ,Electronic, Optical and Magnetic Materials ,Magnetic field ,Magnetization ,Paramagnetism ,Ferromagnetism ,Magnet ,0103 physical sciences ,engineering ,Condensed Matter::Strongly Correlated Electrons ,0210 nano-technology - Abstract
We report magnetic and electrical transport properties of polycrystalline as-cast compound Cr2CoAl having inverse Heusler like XA structure with B2 disorder. Temperature-dependent magnetization (M-T) under zero-field cooled (ZFC) and field cooled (FC) condition and field-dependent magnetization (M-H) studies suggest that this compound is a soft magnetic material below Tc ~ 20.5 K having a very low magnetic moment as it is found that magnetization at 5 K under 50 kOe applied magnetic field is ~0.11μB/f.u. Also, M-T data taken ZFC-FC condition under different applied magnetic fields and M-H data taken at 100 K and 300 K indicate that this compound may have magnetic clusters in paramagnetic matrix. Further analysis and temperature-dependent heat capacity measurement reveal paramagnetic to a short-range ordered ferromagnetic transition near Tc ≈ 20.5 K and also reveal the presence of magnetic clusters within the compound. These magnetic clusters may arise because of B2 disorder in the compound. Temperature-dependent resistivity measurement confirms that the compound Cr2CoAl is metallic as it is found increasing with temperature. Nonlinearity in temperature dependency resistivity data, observed in low- temperature region, follows T2 dependency that generally comes because of electron–electron scattering. Magneto-resistance (MR) is also found to be positive throughout the temperature region from 8 K to 390 K. more...
- Published
- 2021
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50. Computationally-efficient thermal simulations of large Li-ion battery packs using submodeling technique
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Ankur Jain and Vishnu V. Ganesan
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Fluid Flow and Transfer Processes ,Battery (electricity) ,Computer science ,Mechanical Engineering ,Computation ,Nuclear engineering ,Hardware_PERFORMANCEANDRELIABILITY ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Battery pack ,010305 fluids & plasmas ,Coolant ,Volumetric flow rate ,0103 physical sciences ,Thermal ,Automotive battery ,0210 nano-technology ,Reduction (mathematics) - Abstract
Accurate and rapid prediction of temperature distribution in a large Li-ion battery pack comprising thousands of cells is critical for ensuring safety and performance of battery packs for electric vehicles. Due to the multiscale geometry and the large number of individual cells in an automotive battery pack, full-scale thermal simulations typically take a long time to complete. Approaches for rapidly computing the temperature field in a large battery pack without significant loss of accuracy is, therefore, a key technological need. This paper presents thermal simulations of a large, air-cooled Li-ion battery pack containing thousands of individual cells using the submodeling technique. A coarse model that neglects fine geometrical details is first solved, and the results are used to solve a more detailed sub-model. It is shown that this approach results in 7X reduction in computation time while preserving the accuracy of the predicted temperature field. Trade-offs between computation time and accuracy are examined. The submodeling technique is used to investigate the thermal design of a large Li-ion battery pack, including the effect of discharge rate and coolant flowrate on temperature field, and the thermal response to a pulsed spike in discharge rate. Limitations of the submodeling technique are discussed. The technique discussed here is a general one, and may help significantly reduce computation time for thermal design and optimization of large, realistic Li-ion battery packs. more...
- Published
- 2021
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