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Half-metallic ferromagnetic [HMF] nanoparticles are of considerable interest in spintronics applications due to their potential use as a highly spin polarized current source. HMF exhibits a semiconductor in one spin band at the Fermi level Ef and at the other spin band they poses strong metallic nature which shows 100 % spin polarization at Ef. Fe based full Heusler alloys are primary interest due to high Curie temperature. Fe2CrSi Heusler alloys are synthesized using metallic powders of Fe, Cr and Si by mechanical alloying method. X-Ray diffractions studies were performed to analyze the structural details of Fe2CrSi nanoparticles with High resolution scanning electron microscope (HRSEM) studies for the morphological details of nanoparticles and magnetic properties were studied using Vibrating sample magnetometer (VSM). XRD Data analysis conforms the Heusler alloy phase showing the existence of L21 structure. Magnetic properties are measured for synthesized samples exhibiting a soft magnetic property possessing low coercivity (HC = 60.5 Oe) and saturation magnetic moment of Fe2CrSi is 3.16 µB, which is significantly higher than the ideal value of 2 µB from the Slater-Pauling rule due to room temperature measurement. The change in magnetic properties are half-metallic nature of Fe2CrSi is due to the shift of the Fermi level with respect to the gap were can be used as spin sensors and spin injectors in magnetic random access memories and other spin dependent devices. [ABSTRACT FROM AUTHOR]

Heusler Alloy based Cr2CoSi nanoparticles were synthesized by using ball milling. X-ray diffractions studies were used to characterize the crystal structure of Cr2CoSi nanoparticles and magnetic properties were studied using VSM. XRD data analysis confirms the Heusler alloy phase showing the L21 structure. Magnetic properties are measured for synthesized samples having coercivity Hc = 389 Oe, with high saturation magnetization value Ms = 8.64 emu/g and remenance value Mr = 2.93 emu/g. Synthesized Heusler alloy Cr2CoSi nanoparticles can be potential materials for use in Spin polarized based spin sensors, spin devices, magnetic sensors and transducer applications. [ABSTRACT FROM AUTHOR]

The peculiar ternary full Heusler alloy Sr2CoSn nanoparticles are synthesized by co-precipitation method. X- ray diffraction pattern confirms the formation of XA or Xα structure of Sr2CoSn. Using Williamson–Hall plot (W–H plot), we are able to use the uniform deformation model and get low value of strain induced broadening. UV-Visible absorption spectrum shows sharp absorption peak at 210 nm and the estimated band gap energy of Sr2CoSn Heusler alloy nanoparticles is Eg = 4.6 eV (from Tauc plot). The presence of Sr2CoSn with the particle size of approximately 90 nm was observed using high resolution scanning electron microscopy. The magnetization measurements were carried out using VSM and studied M verses H hysteresis studies. [ABSTRACT FROM AUTHOR]

A comparative study was carried out to show the enhancement in optical activity of bimetal oxide nanoparticle (ZnO – TiO2) than metal oxide nanoparticle (ZnO), which can preferably be used for optical applications. The samples were prepared by wet chemical method and crystalline structure of the samples as hexagonal – primitive for ZnO and tetragonal – bcc for ZnO-TiO2 was confirmed by XRD measurements. The average grain size of ZnO – 19.89nm and ZnO–TiO2− 49.89 nm was calculated by Debye- Scherrer formula. The structure and particle size of the sample was analyzed by FESEM images. The direct band gap energy of ZnO (3.9eV) and ZnO – TiO2(4.68eV) was calculated by Kubelka-Munk Function, from which it is clear that the band gap energy increases in bimetal oxide to a desired level than in its pure form. The photoluminescence study shows that the emitted wavelength of the samples lies exactly around the visible region. [ABSTRACT FROM AUTHOR]

The Challenge in employing Ag in CeO2 for lower temperature (LT) Solid Oxide Fuel cell (SOFC) to increase the conductivity and negligible loss due to temperature. The main draw back in IT-SOFC is high activation energy and stability at lower temperature. As per literature - solid electrolyte based on Cerium oxide (CeO2) has less efficiency, for ameliorating the efficiency and stability at lower temperature doped CeO2 are used. This study presents preparation of Ag doped CeO2 (Ce(1-x) AgxO2, x = 0.025, 0.05, 0.1) by combustion technique. The prepared materials structure was studied from XRD and it confirm face centered cubic structure with average size of the particle was 20 nm, 16 nm, and 14 nm respectively. The electrical conductivity properties were studied using electrochemical impedance spectroscopy-Activation energy, Conductivity, Dielectric constant (ε') and Dielectric loss [tan (δ)] characteristic are obtained for temperature range (190-270)°C. [ABSTRACT FROM AUTHOR]

Heusler Alloy based Fe2CeAg nanoparticles were synthesized by using coprecipitation method and reducing a mixture of precursors having FeCl2.4H2O, Ce(NO3)3.6H2O and AgNO3.8H2O under N2 atmosphere with various annealing temperatures and time durations. X-ray diffractions studies were used to characterize the crystal structure of Fe2CeAg nanoparticles and magnetic properties were studied using VSM. XRD data analysis confirms the Heusler alloy phase showing the L21 structure. Magnetic properties are measured for synthesized samples and annealed at various temperatures exhibiting an ultra-soft magnetic property, at 700°C annealed for 5h in N2 atmosphere sample having the lowest coercivity (Hc = 58 (Oe), and high saturation magnetization value (Ms = 1.77 emu/g) in comparison with 800°C and 850°C annealed for 5h in N2 atmosphere sample. At 700°C annealed for 5h in N2 atmosphere sample shows a promising material in Heusler alloy formation and also can possible to use in spintronics, magnetic sensors and transducer applications. [ABSTRACT FROM AUTHOR]

Fe2CoSi based Heusler alloy thin films were deposited on Si (111) wafer (substrate) of varying thickness using ultra high vacuum DC magnetron sputtering. The structural behavior was observed and found to be hold the L21 structure. The deposited thin films were characterized magnetic properties using vibrating sample magnetometer; the result shows a very high saturated magnetization (Ms), lowest coercivity (Hc), high curie transition temperature (Tc) and low hysteresis loss. Thin film thickness of 75 nm Fe2CoSi sample maintained at substrate temperature 450°C shows the lowest coercivity (Hc=7 Oe). In general, Fe2CoSi Heusler alloys curie transition temperature is very high, due to strong exchange interaction between the Fe and Co atoms. The substrate temperature was kept constant at 450°C for varying thickness (e.g. 5, 20, 50, 75 and 100 nm) of thin film sample. The 75 nm thickness thin film sample shows well crystallanity and good magnetic properties, further squareness ratio in B-H loop increases with the increase in film thickness. [ABSTRACT FROM AUTHOR]

Ce0.90Fe0.1O2, cubic structure exhibits interesting electrical property-due to the effects of oxygen vacancies. Electrical response of nanocrystalline Ce0.90Fe0.1O2 material as a function of temperature was investigated using impedance spectroscopy. A change was observed in Nyquist plot for the temperature 903k, which has been analysed in terms of localized and delocalized electrons. An interesting behaviour of temperature stimulate semiconductor to metal like transition was observed in frequency dependent dielectric constant (ε′) and frequency dependent dielectric loss(tan δ). Frequency dependence on the real and imaginary part of impedence with respect to temperature aids the presences of semiconductor to metal like transition in Ce0.90Fe0.1O2. [ABSTRACT FROM AUTHOR]