Study of Induced Magnetic Anisotropy by Lattice Distortion in Cobalt Ferrite Thin Film Grown on (Mg,Sn)3O4 Buffer Layers

We have investigated structural and magnetic properties of cobalt ferrite (CFO)(001) epitaxial thin films grown by RF magnetron sputtering method on (Mg,Sn)₃O₄ (MSO) buffer layers to induce large perpendicular magnetic anisotropy (PMA) through the magneto-elastic effect. Tuning of the CFO distortion was demonstrated by changing the film thickness of CFO. Torque measurements revealed that a 5-nm thick CFO thin film showed the PMA constant K_u = 25.8±1.3 Merg/cm³ at room temperature, which is extraordinarily large for a ferromagnetic oxide.