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Reduced Graphene Oxide/SiO2 Nanoparticles were synthesized by a three-step process. First, SiO2 nanoparticles have been synthesized using solvothermal synthesis, and second, graphene oxide is prepared using modified Hummer's method. Finally, SiO2 nanoparticles have been assembled between graphene oxide layers using hydrothermal synthesis technique. In situ reduction of graphene oxide layers is carried out via thermal reduction during hydrothermal treatment thus avoiding the use of harmful reducing agents. Formation of amorphous SiO2 nanoparticles has been confirmed using X-ray diffraction and scanning electron microscopy. Complex impedance data of SiO2 and SiO2/reduced graphene oxide composite have been modelled using Cole-Cole formalism. Results show that there a decrease of three orders of magnitude in the resistivity of SiO2/reduced graphene oxide composite in comparison to bare SiO2 particles which has a resistivity of an order of 10 5 Om. [ABSTRACT FROM AUTHOR]

A nanocrystalline Cr-doped ZnO has been prepared by refluxing method. The samples were characterized using XRD and impedance spectroscopy. The XRD pattern shows the crystalline nature of the sample and well confirms the successful doping Cr into the host lattice. The conductivity of the sample measured in the temperature range 303-603K and in the frequency range 10Hz-1MHz. The temperature dependent dc conductivity and hopping frequency show Arrhenius behavior. AC conductivity data were analyzed using Jonscher's power law. Modulus data were analyzed using Bergman modified KWW function. Temperature dependent capacitance shows a sharp peak at 540K which may be due to ferroelectric nature of the material. [ABSTRACT FROM AUTHOR]

The dielectric loss peaks are rarely seen in highly conducting solids due to conductivity contribution to the dielectric loss of material. LiCoO2 for the temperature range of l48K to 248K show dielectric relaxation at high frequencies with dc conductivity contribution. Conduction and dielectric relaxation of the material is studied with Cole-Cole type combined 'pinned dipole' relaxation from hopping charges and 'free dipole' relaxation due to host matrix. [ABSTRACT FROM AUTHOR]

Nanocrystalline V2O5 was synthesized by solvothermal technique, which has potential application as electrode material in supercapacitors. The graphene oxide (GO) was prepared by modified Hummer's method. The V2O5/ reduced graphene oxide (RGO) composite was synthesized using surfactant free hydrothermal technique to enhance the functionality in terms of conductivity and surface area of V2O5. The structural characterization was accomplished through X-ray diffraction and Raman spectroscopy. Morphology was identified by SEM and surface area of VRGO was enhanced by 8 times in comparison with V2O5 nano particles, as confirmed through BET surface area analysis. Electrical characterization was done through impedance spectroscopy and the results showed decrease in sample resistance after wrapping V2O5 with RGO. [ABSTRACT FROM AUTHOR]

Nano-crystalline Mn0.5Zn0.5Fe2O4 was synthesized by chemical co-precipitation method and characterized with X-ray diffraction. Ac electrical impedance data are taken for the frequency range of 1Hz to 1MHz for various temperatures from 303K to 483K. The ac electrical conduction deviates from the Debye type relaxation which indicates polaron type conduction. In the present study unique anomalous relaxation function in time and frequency domain is used to investigate deviation from the Debye relaxation. The physical basis of anomalous or non-Debye process is explained in terms of change in Debye dipole μD=ρrD of charge ρ into gρ due to the molecular charge interaction and defect disorder. This interaction shifts the Debye relaxation rate τ to a slow relaxation rate τg. The fraction 0

Nanocrystalline LiMnPO4 material was synthesized by template free sucrose assisted hydrothermal method. The material possesses the orthorhombic crystal structure with Pnma, space group having four formula units. The GO was prepared by the hummer's method and it was reduced graphene oxide (rGO) with hydrazine hydrate in the presence of nitrogen atmosphere. LiMnPO4 material was wrapped by the rGO to increase its conductivity. The structural characterization was accomplished through X-ray diffraction, FT-IR and Raman spectroscopy. Morphology was identified by the SEM, Electrical characterization was done through impedance spectroscopy and the results were reported. [ABSTRACT FROM AUTHOR]

Electric relaxation in ion conducting materials is still interesting due to its deviation from the ideal resistor capacitor behavior due to correlated hopping ion dynamics. In the present study we have used an unusual complex anomalous relaxation function which has a functional form in both frequency and time domain to understand the correlated motion of ions. Ion conducting Na4Nb(1-x)Cd2.5xP3O12 (x=0.1, 0.25, 0.5) glass are prepared and its ac impedance spectroscopic data are investigated for ion dynamics and electric relaxation have studied in terms of fast and slow process. [ABSTRACT FROM AUTHOR]

A dense core rectangular shaped nanocrystalline LiMnPO4 material was synthesized by template free sucrose assisted hydrothermal synthesis. The material possess orthorhombic crystal structure with Pnma, space group having four formula units. The structural characterization was accomplished through X-ray diffraction, thermo gravimetry/differential thermal analysis. Morphology was identified by the SEM, VSM was used to verify the magnetic behavior of the material and electrical characterization was done through impedance spectroscopy and the results were reported. [ABSTRACT FROM AUTHOR]

Ion conducting Na2NbZnP3O12 glass is investigated for the mechanism of the ion dynamics and non-Debye relaxation. The impedance spectroscopic data of the sample is taken for a frequency range of 100Hz to 1MHz for a temperature range of 393K to 513K. Anomalous relaxation function is used to study the microscopic mechanism of ion dynamics through the complex relaxation time. The physical picture of the ion dynamics have studied with the trapped and hopping charge carriers. The many particle displacement function and its scaling are used to understand the length scale of ion dynamics. [ABSTRACT FROM AUTHOR]

A phase pure nanocrystalline Li2Ni1-xMgxTiO4 cation disordered rock salt phase materials are synthesized by sol-gel technique. The structural characterization is accomplished through XRD, TG/DTA and SEM. The electrical property of the material is investigated through impedance spectroscopy. The magnetic property of the samples is studied through the vibration sample magneto meter (VSM). The VSM data at room temperature shows the lack of ferromagnetic interaction indicates the absence of different valence states. The proximity between activation energies of dc conduction and conduction relaxation indicate that while conducting and relaxing ion has to overcome the same energy-barrier. [ABSTRACT FROM AUTHOR]

The nanocrystallites of LiNaSO4 were prepared by co-precipitation method at room temperature and characterized by XRD, SEM and TG-DSC measurements. The average crystallite size is found to be 46 nm. The DSC curve shows two endothermic peaks at 255.8 °C and 508.8 °C. The electrical conductivity is studied as functions temperature and frequency and results are reported. The activation energy obtained for the stable phase of LiNaSO4 is 1.19 eV. The material becomes superionic conductor at high temperature phase. [ABSTRACT FROM AUTHOR]

Olivine structured material shows specific capacities up to 170mAh/g and can be charged in a very short time. LiMPO4, (M=transition metal ion) does not consists of heavy metal and have no memory loss like Ni-Cd, Ni-metal hydride solutions. Benefit of LiMPO4 is its flexibility for the cell design and battery applications. Li based LiCoPO4 of Orthophosphate family is synthesized by template free sucrose assisted hydrothermal method. Olivine structured compounds possess orthorhombic crystal structure with Pnma, pmnb space group having four formula units. The material is characterized through different techniques like XRD, FTIR, SEM, VSM and electrical characterization is done through impedance spectroscopy and the results are reported. [ABSTRACT FROM AUTHOR]

A phase-pure nanocrystalline Li2MgZrO4 material is synthesized by solution combustion synthesis. In this study citric acid is used as fuel and pH of the homogenous solution is maintained. The material is crystallized in a cubic rock-salt structure of space group Fm[larger_open_square]3m. TEM analysis revealed that the material is formed as nano-crystallites. The structural characterization is accomplished through X-ray diffraction, thermogravimetry, differential thermal analysis, transmission electron microscopy and electrical characterization is done through impedance spectroscopy and the results are reported. [ABSTRACT FROM AUTHOR]

A phase-pure nanocrystalline Li2NiZrO4 material is synthesized by solution combustion synthesis. In this study citric acid is used as fuel and pH of the homogenous solution is maintained. The material is crystallized in a cubic rock-salt structure of space group Fm□3m. TEM analysis revealed that the material is formed as nano-crystallites. The structural characterization is accomplished through X-ray diffraction, thermo gravimetry/differential thermal analysis, transmission electron microscopy and electrical characterization is done through impedance spectroscopy and the results are reported. [ABSTRACT FROM AUTHOR]

We report the electrical relaxation in ion conducting Li4Nb1-xZn 2.5xP3O12. These glasses were prepared by conventional melt quenching method. The electrical relaxation has been investigated both in ac conductivity as well as electric modulus formalisms. The conductivity isotherms show a transition from frequency independent dc region to dispersive region where the conductivity increases with increasing frequency. The power law dispersion of the ac conductivity scales regardless of the variation of x in TTSP scheme, and therefore suggests that relaxation in these glasses is independent of the temperature and composition.. [ABSTRACT FROM AUTHOR]