Superconducting gap induced barrier enhancement in a BiFeO3 -based heterostructure

Abstract

We report the synthesis and characterization of an epitaxial heterostructure composed of multiferroic BiFeO3 and superconducting YBa2 Cu3 O7-δ thin films grown on (001) SrTiO3. Both the superconductivity of YBa2 Cu3 O7-δ and the ferroelectricity of BiFeO3 are retained in the heterostructure. Current density-electric field characteristics measured from 30 to 170 K suggest a Schottky-emission-like transport at the BiFeO 3 / YBa2 Cu3 O7-δ interface. Furthermore, the temperature dependence of the barrier height shows an anomalous enhancement at TC, indicating an intimate coupling between the multiferroic and the superconducting layers. © 2010 American Institute of Physics.