Effect of Silver Substitution on Electrical Transport and Magnetoresistance of La0.8Ca0.2MnO3

Abstract

Abstract In this work, we have investigated the effect of silver substitution on electrical transport behavior and magnetoresistance of La0.8- xAgxCa0.2MnO3 (x = 0 and 0.05). Preparation and study of structural and microstructure of both samples have been reported on previous work. Temperature-dependent resistivity has been measured at temperature range of 15-285 K with zero field cooling. Magnetoresistance effect has been measured at 15, 100, and 285 K with magnetic field up to 1 T. The electrical transport behavior of both samples are quite well described by a theory based on the Percolation model. The electrical conduction mechanism at low temperature can be explained by a theory based on Kondo-like spin-dependent scattering, electron-electron, electron–magnon, and electron-phonon scattering. It was found that silver substitution increases the metal-insulator transition temperature (TM-I) from 197.55 to 277.56 K, and Curie temperature (Tc Mod) from 217.25 to 278.65 K. Moreover, the maximum magnetoresistance value of both samples was obtained at 15 K.