Magnetization reversal by electric field in Co substituted bismuth ferrite thin film

Electric field manipulation of magnetization is intensively investigated because of potential application in low-power-consumption non-volatile magnetic memory devises. Ferroelectric BiFeO₃ has a cycloidal space-modulated spin structure with a periodicity of 62 nm superimposed on the G-type antiferromagnetic structure. The presence of cycloidal ordering prohibits the appearance of net ferromagnetic magnetization due to spin canting and a linear magnetoelectric effect. We have observed a spin structure transition from low-temperature cycloidal one to high-temperature collinear one at ~200 K using Mössbauer spectroscopy in rhombohedral BiFe_0.1Co_0.9O₃ thin films fabricated by PLD on SrTiO₃ (STO) (111) substrate. Spontaneous magnetization of 0.03 u_B/f.u. confined in a magnetic easy plane perpendicular to the electric polarization is generated by Dzyaloshinskii-Moriya interaction. Films fabricated on GdScO₃ (110) substrate has out-of-plane component of magnetization which can be observed by MFM. It is demonstrated that the out-of-plane magnetization can be reversed by electric polarization reversal using PFM at room temperature.