EFFECT OF STRAIN ON THE TRANSPORT PROPERTIES OF THE MANGANITE

Abstract

The effect of strain on the resistivity and thermopower of ferromagnetic manganites has been examined based on the model that incorporates the electron-lattice interaction through the Jahn–Teller effect and an effective hopping determined by nearest neighbor spin–spin correlation of t2g electrons. The metal insulator transition temperature associated with resistivity decreases with increase in strain. In the presence of large strain the system remains in the semiconducting state. Thermopower (S) is positive and increasing function of strain and it exhibits a maximum with temperature. The temperature where maximum of S appears, shifts towards higher (lower) value in the presence of magnetic field (strain). A large magneto-thermopower that depends on strain is obtained around metal–insulator transition.