Strain Engineering of Magnetic Anisotropy in Epitaxial Films of Cobalt Ferrite

Perpendicular magnetic anisotropy (PMA) energy up to Ku = 6.1 ± 0.8 MJm−3 is demonstrated in this study by inducing large lattice distortion exceeding 3% at room temperature epitaxially distorted cobalt ferrite Co0.73Fe2.18O4 (001) thin films. Although the film materials include no rare-earth elements or noble metals, observed larger than that of neodymium-iron-boron compounds for high-performance permanent magnets. The PMA attributed significantly enhanced magneto-elastic effects, which are pronounced films with epitaxial structures upon introducing a control layer composition Mg2−xSn1+xO4. Surprisingly, induced can be quantitatively explained terms agreement between local crystal field Co2+ and phenomenological model, indicating linear response sufficiently valid even under distortions as 3.2%. Controlling tetragonal deformation using non-magnetic spinel ferrites could promising protocol developing anisotropies.