Adiabatic polaron transport in La_0.9Pb_0.1MnO₃ manganites

Abstract

A study of single-phase La 0.9 Pb 0.1 MnO 3 compositions is presented. The temperature dependence of the EPR line intensity and resistivity evidence a spin-lattice interaction in the paramagnetic region near the Curie point. In the high temperature region a spin-spin interaction is dominant. is not yet clear enough despite a large number of publications on this problem. The difficulties consist in a close connection between structure, electronic and magnetic properties of perovskite-type manganites. Resonance methods can give useful information about the internal dynamics of these materials, especially near the Curie temperature, T C , where they show the highest value of the CMR effect. Electron paramagnetic resonance (EPR) has been studied in a variety of lanthanum manganites. Some authors [4,5] attributed the temperature dependence of the EPR linewidth to a spin-phonon interaction (one-phonon relaxation process) and explained it by spin-lattice relaxation of exchange coupled Mn