Electrical transport in the ferromagnetic state of silver substituted manganites La_1−xAg_xMnO₃ (x = 0.05 and 0.1)

Abstract

The present study focuses on a quantitative analysis of electrical resistivity in monovalent-doped manganites La 1Àx Ag x MnO 3 (x 5 0.05 and 0.1). The electrical resistivity data in the ferromagnetic (FM) metallic phase are analyzed by considering a temperature-independent inelastic scattering of the electrons (due to domain and grain boundaries, defects, etc.) and other temperature-dependent elastic scattering mechanisms (electron-electron, electron-phonon, and electron-magnon). The Debye and Einstein temperatures are deduced from the model Hamiltonian containing potential energy contribution from the long-range Coulomb, van der Waals (vdW) interaction, and shortrange repulsive interaction up to the second-neighbor ions. The electron-phonon scattering partially describes the reported FM metallic resistivity behavior with temperature for La 1Àx Ag x MnO 3 (x 5 0.05 and 0.1). The T 2 and T 4.5 terms accounting for electron-electron and electron-magnon interactions are essential for the correct description of resistivity. The Mott-Ioffe-Regel criterion for metallic conductivity is valid, and k F l ; 1, e F s ; 1.