Continuous strain-mediated perpendicular magnetic anisotropy in epitaxial (111) CoFe2O4 thin films grown on LiTaO3 substrates

• Published in: Journal of applied physics 2024-03, Vol.135 (12)
• Main Authors: Wang, S., Hu, L., Zhang, G. D., Wei, R. H., Song, W. H., Zhu, X. B., Sun, Y. P.
• Format: Article
• Language: English
• Subjects: Anisotropy; Cobalt ferrites; Epitaxial growth; Induced magnetic anisotropy; Lattice strain; Magnetic thin films; Magnetoelastic effect; Spintronics; Substrates; Thermal expansion; Thin films
• ISSN: 0021-8979; 1089-7550
• DOI: 10.1063/5.0185399

Perpendicular magnetic anisotropy (PMA) in magnetic thin films has attracted much attention due to its potential applications in spintronics devices. Here, we report the continuous strain-mediated PMA in epitaxial (111) CoFe 2O 4 (CFO) thin films grown on (0001) LiTaO 3 substrates. A large variation in lattice strain ( ∼ 0.9 %) in a continuous way is realized in the CFO thin films by changing substrate temperature during deposition due to the difference in the thermal expansion coefficient between CFO and LiTaO 3. As a result, the PMA of the (111) CFO thin films can be continuously mediated by the strain with uniaxial magnetic anisotropy energy in the range of 0.12 - 14.69 × 10 6 erg/cm 3. Furthermore, the strain as well as the consequent PMA in the (111) CFO thin films can be maintained within the thickness of 25–205 nm, which is consistent with the scenario of the magnetoelastic effect. Our results reveal that the CFO/LiTaO 3 system can be regarded as an ideal platform to realize robust PMA and its continuous strain tuning in the (111) CFO thin films by virtue of strain-induced magnetic anisotropy.