Enhanced multiferroic properties of tetragonally strained epitaxial BiMnO3 thin films grown on single crystal Rh substrates

摘要

Epitaxial BiMnO3 (BMO) thin films with tetragonally strained structures were fabricated and their multiferroic properties were investigated in order to improve the leakage current characteristics of the BMO thin films and to secure the excellent multiferroic properties. The x-ray diffraction experiment confirmed that the BMO thin films grown on the Rh substrates had noticeably tetragonally strained structure compared to the BMO thin films on the Nb doped SrTiO3 substrates. As a result, the leakage current characteristics of the BMO thin films were improved, and the ferroelectric hysteresis loops were also excellent enough to be used for the nonvolatile memory devices. In addition, it was confirmed that the BMO thin films had a multiferroic property by measuring the ferromagnetic hysteresis loops of the BFM thin films, and it was confirmed that the ferromagnetic properties were improved by the tetragonal strain. Further, the band gaps of the BMO thin films were measured and it was confirmed that the band gap of the strained BFO thin film was increased.