Showing papers by "Ajit Kumar Meikap published in 1993"
TL;DR: The results of a comprehensive study of localization and electron-electron interaction effects in doped polypyrrole films show the conductivity when temperature T>10 K can be explained by Mott's variable-range hopping model and the density of states and hopping distance can be calculated from these data.
Abstract: We report the results of a comprehensive study of localization and electron-electron interaction effects in doped polypyrrole films. We have measured the electrical conductivity and magnetoconductivity within the temperature range 1.8 K≤T≤300 K. The observed temperature dependence of dc conductivity cannot be explained either by the band-conduction model or by assuming a temperature-dependent energy gap. However, the conductivity when temperature T>10 K can be explained by Mott's variable-range hopping model and the density of states and hopping distance can be calculated from these data
33 citations
TL;DR: In this article, the results of an extensive study of localization and electron-electron interaction effects in thin cadmium films with thickness ranging from 80 A to 350 A were reported.
Abstract: We report here the results of an extensive study of localization and electron-electron interaction effects in thin cadmium films with thickness ranging from 80 A to 350 A. Measurements of the resistance as a function of both temperature and magnetic field have allowed us to separate the contributions of localization and electron-electron interaction. The low resistive films of thicknesses 300 A and 350 A do not show any localization. The resistance of these samples decreases logarithmically with decreasing temperature below 10 K, while a ln(T) increases in resistance is observed for the high resistive films of thickness in the range of 80–120 A. Magnetoresistance of low resistive samples obeys the expression ΔR(H)/R(O)=AT
n. But, both the resistance and magnetoconductance of the high resistive films are well explained by weak localization and electron-electron interaction effect. From the magnetoconductance measurement, we have calculated the inelastic scattering time (τ
i
) and the spin-orbit scattering time (τ
so
). The magnitude of spin-orbit scattering time is smaller than the inelastic scattering time. The inelastic scattering has been shown to arise due to the electron-electron scattering and the absolute magnitude of this scattering rate agrees reasonably well with the theory within the temperature range 1.8 K≤T≤5 K. At higher temperature (5 K
4 citations
TL;DR: In this article, the low temperature resistivity and magnetoconductance of two and quasi two dimensional disordered In/Ni/In sandwich has been measured to investigate the different scattering time by the method of weak antilocalization.
1 citations