Effects of ferroelectric-poling-induced strain on the transport and magnetic properties of La₇ /₈Ba₁/₈MnO₃thin films

Abstract

We have investigated the effects of the strain induced by ferroelectric poling on the transport and magnetic properties of La₇/₈Ba₁/₈MnO₃(LBMO) thin films epitaxially grown on ferroelectric 0.67Pb(Mg₁/₃Nb₂/₃)O₃-0.33PbTiO₃(PMN–PT) single-crystal substrates. The ferroelectric poling reduces the in-plane tensile strain of the film, giving rise to a decrease in the resistivity and an increase in the magnetization, Curie temperature, and magnetoresistance of the LBMO film. These strain effects are explained within the framework of coexisting phases whose volume fractions are modified as a result of the reduction in the tetragonal distortion of MnO₆ octahedra induced by ferroelectric poling. An investigation of the effects of polarization reversal on the transport properties of the LBMO film indicates that the ferroelectric-poling-induced strain effects dominate over the ferroelectric field effects in the LBMO/PMN–PT structure.