Heteroepitaxial growth and multiferroic properties of Mn-doped BiFeO_3 films on SrTiO_3 buffered Ⅲ-Ⅴ semiconductor GaAs

摘要

Epitaxial Mn-doped BiFeO_3 (MBFO) thin films were grown on GaAs (001) substrate with SrTiO_3 (STO) buffer layer by pulsed laser deposition. X-ray diffraction results demonstrate that the films show pure (001) orientation, and MBFO (100)//STO(100), whereas STO (100)//GaAs (110). Piezoresponse force microscopy images and polarization versus electric field loops indicate that the MBFO films grown on GaAs have an effective ferroelectric switching. The MBFO films exhibit good ferroelectric behavior (2P_Γ ～ 92 μC/cm~2 and 2EC ～ 372 kV/cm). Ferromagnetic property with saturated magnetization of 6.5 emu/cm~3 and coercive field of about 123 Oe is also found in the heterostructure at room temperature.