Effects of ferroelectric polarization and converse piezoelectric effect induced lattice strain on the electrical properties of La0.7Sr0.3MnO3 thin films

Thin films of La0.7Sr0.3MnO3 (LSMO) have been grown on the ferroelectric 0.68Pb(Mg1∕3Nb2∕3)O3–0.32PbTiO3 (PMN-PT) single-crystal substrates. The ferroelectric polarization of the PMN-PT induces a large decrease in the resistivity and an upward shift in the Curie temperature of the LSMO films, which was interpreted in terms of the ferroelectric polarization induced large reduction of the biaxial tensile strain in the LSMO films. The resistivity of the LSMO films can be dynamically tuned by applying dc electric fields across the polarized PMN-PT. The analyses of the results indicate that the electric field induced lattice strain via converse piezoelectric effect in the PMN-PT controls the strain states and hence the resistivity and Curie temperature of the LSMO films.