Electric-Field-Tunable Transport and Photo-Resistance Properties in LaMnO3−x/PMN-PT Heterostructures

Abstract

Multiferroic heterojunctions are promising for application in low-power storage and spintronics due to their magnetoelectric coupling properties. Controlling the magnetic and transport properties of magnetic materials by external stimuli and then realizing advanced devices constitute the key mission in this field. We fabricated a multiferroic heterostructure consisting of a ferroelectric single-crystal (001)-0.7Pb(Mg1/3Nb2/3)O3-0.3PbTiO3 substrate and an epitaxial 40 nm LaMnO3−x film. By applying dc electric fields to the ferroelectric substrate, the resistance and the photo-resistance of the LaMnO3−x film could be significantly modulated. With the electric field increasing from 0 to +4.8 kV/cm, the photo-resistance increased by ~4.1% at room temperature. The curve of photo-resistance versus the cycling electric field has a butterfly shape due to the piezoelectric strain effect. Using in situ X-ray diffraction measurements, the linear relationship of the strain and the electric field was quantitatively studied.