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Papers by Kriti Seth
Journal of the American Ceramic Society, 2018
Compounds of undoped and samarium (Sm) doped ZnO have been prepared by standard solid state react... more Compounds of undoped and samarium (Sm) doped ZnO have been prepared by standard solid state reaction method. X-ray diffraction (XRD), Williamson-Hall (W-H) analysis, Transmission Electron Microscopy (TEM), temperature dependent electrical and dielectric studies have been done to characterize these materials. Inclusion of Sm as dopant in hexagonal wurtzite ZnO changes the lattice parameters to a small extent with some Sm aggregation at higher concentration. Also, the mean particle sizes of ZnO:Sm compounds showed an inter-correlation with the Scherrer method, W-H analysis as well as with TEM results. The electrical resistivity depicts an exponential decay and metal-semiconductor transition (MST) at ~300 K for the pristine sample whereas there is large decrement in the resistivity with Sm doping. The analysis of of ZnO suggests that the power law is obeyed and indicated an increase in the ac conductivity with Sm content. The mechanism behind this type of conductivity is elucidated by small polaron tunneling (SPT) model of conductivity. The dependence of ln dc on the temperature inverse shows that the traps of electrons are thermally activated such that low and high temperature activation energies confirm the presence of vacancies and interstitials of both O and Zn ions. Thus, a high value of dielectric Accepted Article This article is protected by copyright. All rights reserved. constant makes these materials suitable for high frequency and charge storage device applications.
3RD INTERNATIONAL CONFERENCE ON CONDENSED MATTER AND APPLIED PHYSICS (ICC-2019)
The structural and optical properties of pure and TiO2 doped WO3 samples have been analyzed to st... more The structural and optical properties of pure and TiO2 doped WO3 samples have been analyzed to study the modification of the electronic structure and disorder developed in the samples due to TiO2 doping. The samples are of single phase in nature and no secondary phase or any impurity peak has been detected from structural analysis. The incorporation of Ti ions introduces disorder in the system which leads to slight degradation in crystallinity of the samples with increasing doping. There is decrease in grain size with increase in TiO2 doping concentration. The band gap shows red shift with doping .This is due to the formation of impurity band and trapping of Ti atoms which leads to the generation of the defect states within the forbidden band. Photoluminescence (PL) spectra shows gradual decrease of intensity of blue emission peaks with increasing TiO2 doping. These structural and optical studies manifest increase in defect or disorder in the system with increasing TiO2 doping.
Journal of the American Ceramic Society, 2018
Compounds of undoped and samarium (Sm) doped ZnO have been prepared by standard solid state react... more Compounds of undoped and samarium (Sm) doped ZnO have been prepared by standard solid state reaction method. X-ray diffraction (XRD), Williamson-Hall (W-H) analysis, Transmission Electron Microscopy (TEM), temperature dependent electrical and dielectric studies have been done to characterize these materials. Inclusion of Sm as dopant in hexagonal wurtzite ZnO changes the lattice parameters to a small extent with some Sm aggregation at higher concentration. Also, the mean particle sizes of ZnO:Sm compounds showed an inter-correlation with the Scherrer method, W-H analysis as well as with TEM results. The electrical resistivity depicts an exponential decay and metal-semiconductor transition (MST) at ~300 K for the pristine sample whereas there is large decrement in the resistivity with Sm doping. The analysis of of ZnO suggests that the power law is obeyed and indicated an increase in the ac conductivity with Sm content. The mechanism behind this type of conductivity is elucidated by small polaron tunneling (SPT) model of conductivity. The dependence of ln dc on the temperature inverse shows that the traps of electrons are thermally activated such that low and high temperature activation energies confirm the presence of vacancies and interstitials of both O and Zn ions. Thus, a high value of dielectric Accepted Article This article is protected by copyright. All rights reserved. constant makes these materials suitable for high frequency and charge storage device applications.
3RD INTERNATIONAL CONFERENCE ON CONDENSED MATTER AND APPLIED PHYSICS (ICC-2019)
The structural and optical properties of pure and TiO2 doped WO3 samples have been analyzed to st... more The structural and optical properties of pure and TiO2 doped WO3 samples have been analyzed to study the modification of the electronic structure and disorder developed in the samples due to TiO2 doping. The samples are of single phase in nature and no secondary phase or any impurity peak has been detected from structural analysis. The incorporation of Ti ions introduces disorder in the system which leads to slight degradation in crystallinity of the samples with increasing doping. There is decrease in grain size with increase in TiO2 doping concentration. The band gap shows red shift with doping .This is due to the formation of impurity band and trapping of Ti atoms which leads to the generation of the defect states within the forbidden band. Photoluminescence (PL) spectra shows gradual decrease of intensity of blue emission peaks with increasing TiO2 doping. These structural and optical studies manifest increase in defect or disorder in the system with increasing TiO2 doping.