We report on the temperature dependence of resistivity in La 0.7-xPrxMnO3 (x=0, 0.5, 0.7) bulk samples in order to explore the hopping transport behavior with the Coulomb effects for the colossal magnetoresistance materials. The experimental observations in La 0.7-xPrxPb0.3MnO3 (x=0.5, 0.7) bulk samples reveal the exponential temperature dependence of resistivity ρ(T)∞ [T1/T)n] with n = 1/2, when system was the paramagnetic (PM) insulator at the high temperature range (T>Tp). Evidence for the hopping conduction with Coulomb effects is presented By using the approximate method of the VRH conduction in the localization regime base on Efros and Shklovskii model [A. L. Efros and B. I. Shklovskii, J. Phys. C, Solid State Phys. 8, L49 (1975)], the localization length of eg electrons can be estimated with the relationship, ξ=2.8e2/ (4πε0κkBT1). The reasonable results of localization length can be evaluated to explain the possibility of the presence of the Coulomb interactions in these CMR materials.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics