Mechanical stability of ferrimagnetic CoFe2O4 flexible thin films

We fabricated high-quality ferrimagnetic CoFe₂O₄ (CFO) thin films on a mica substrate using a pulsed laser deposition technique. High-resolution X-ray diffraction and transmission electron microscopy revealed that the film grew epitaxially with the relationships of CFO <1-10> || Mica 010] and CFO 111] || Mica 001]. The films were highly flexible in terms of both inward and outward bending, and exhibited clear ferrimagnetic hysteresis with weak anisotropy in both the in-plane and out-of-plane directions. We observed that the magnetization of CFO films was robust against mechanical stimuli without microcracks. The remnant magnetization and coercive field were within 8% and 11% over a strain of ±0.54%. As the number of bending cycles increased, the magnetic easy axis became more closely aligned to the out-of-plane direction, without any noticeable change in domain size.