[21] Multiferroic BiMnO₃ thin films with double SrTiO₃ buffer layers

High quality BiMnO₃ thin films with double SrTiO₃ buffer layers were fabricated on Pt∕Ti∕SiO₂∕Si and SrTiO₃ substrates, in which SrTiO₃ buffer layers were used to reduce leakage current in BiMnO₃ thin films. The SrTiO₃ buffer layers had a thickness of about 5nm obtained from the fitting of ellipsometer data, which gave the remarkable enhancement in leakage current. BiMnO₃ thin films exhibited the ferromagnetic transition with the Curie temperature of about 105K. The Pt∕SrTiO₃∕BiMnO₃∕SrTiO₃∕Pt and SrRuO₃∕SrTiO₃∕BiMnO₃∕SrTiO₃∕SrRuO₃ capacitors showed good ferroelectric properties with the remanent polarization of about 9 and 16𝜇C/cm², respectively.