Large intrinsic magnetization in an epitaxial BiFeO3/NdGaO3system

We report a comparative study of the crystal structure and magnetic properties between (001) oriented epitaxial films grown on and substrates without any magnetic parasitic phase. The 15 nm film deposited on a substrate shows substantially high magnetization as compared to an identically thick film deposited on a substrate. Detailed structural analysis revealed that the high magnetization is associated with a monoclinic (Cm) like distortion of the crystal structure. We corroborated our experimental findings with first principles density functional theory calculations which suggested a saturation magnetization (266 emu/cc) close to the experimentally obtained one and a ferromagnetic ground state with the high spin moment in the Cm phase.