Isothermal electric switching of magnetization in Cr₂O₃/Co thin film system

We investigated the magnetoelectric properties of Cr₂O₃/Co all-thin-film exchange coupling system with Cr spacer layer. In this system, significantly small coercivity (H_c < 50 Oe) was obtained by the Cr spacer layer insertion between Cr₂O₃ and Co layers. Owing to the small H_c, exchange bias field, H_ex, larger than H_c was achieved. It enabled us to observe magnetization switching at a zero magnetic field, when H_ex was reversed by magnetoelectric effect of Cr₂O₃ layer. Finally, we demonstrated the isothermal magnetoelectric switching of magnetization in the Cr₂O₃/Cr/Co all-thin-film system. By changing the direction of the electric field during the isothermal magnetoelectric switching process, both H_ex and magnetization at a zero magnetic field were reversed back and forth, i.e., isothermal magnetization switching by an electric field was achieved.