Tuning the crystallographic orientation and magnetic properties of multiferroic CuO epitaxial film on single crystalline SrTiO3 substrates

Abstract

We report a comparative study between the crystal structure and magnetic properties of multiferroic epitaxial CuO thin films grown on (001) and (110) oriented SrTiO3 substrates. CuO thin films were successfully grown along the [010] direction, which is also the direction of their ferroelectric polarization, on (110) oriented SrTiO3 substrates. We correlate our structural findings with the magnetic properties. It was observed that the heterostructure with the CuO film grown along the [010] direction shows distinct anomalies in the temperature dependent magnetization plot at 213 K and 230 K, whereas no such anomaly was observed in the case of the heterostructure grown on the (001) SrTiO3 substrate with the [111] CuO film. Buffered MgO layers were used between the CuO layer and the substrate to improve the crystalline quality of the CuO film.