Electroresistance and field effects in epitaxial thin films of Pr0.7Sr0.3MnO3

Highly epitaxial thin films of Pr0.7Sr0.3MnO3 were grown on (100) SrTiO3 single crystal substrates by laser ablation. Similar to other manganite compounds, these Pr0.7Sr0.3MnO3 films exhibited remarkable magnetoresistance. Application of electric currents could induce a remarkable reduction in resistivity, demonstrating a strong electroresistance effect. The ratio of the resistance variation, ER = [R(0)−R(I)]/R(I), is about 33% at metal-insulator transition temperature. Using a planar field effect configuration, significant field modulation of the metal-insulator transition was achieved. The observed field effects were discussed based on the strong interactions between carrier spins and localized spins in Mn ions, as well as the percolative mechanism of phase separation.