Effect of ferroelectric polarization switching on the electronic transport properties of La0.8Ca0.2MnO3 film

La0.8Ca0.2MnO3 thin film grown on 0.67Pb(Mg1/3Nb2/3)O3-0.33PbTiO3 (PMN-PT) substrate has shown very interesting transport properties, which is modulated by the ferroelectric polarization switching in the substrate. The ferroelectric poling reduces the in-plane strain by about 0.135% with the applied piezovoltage of 500 V to PMN-PT substrate. The resistance is lowered and the metal-insulator transition temperature (Tp) is increased due to the reduced in-plane strain. Moreover, it is shown that the ferroelectric field effect competes strongly with the strain effect especially when the temperature is lowered below Tp in our film.