CoPt-Al2O3 Nanocomposite Films: Synthesis, Structure, and Magnetic Properties

Zhigalov, V. S., Bykova, L. E., Myagkov, V. G., Pavlova, A. N., Volochaev, M. N., Matsynin, A. A., & Patrin, G. S. Journal of Surface Investigation: X-ray, Synchrotron and Neutron Techniques. DOI: 10.1134/S102745102001022X

―The structure and magnetic properties of CoPt–Al2O3 nanocomposite films synthesized by the annealing of Al/(Co3O4 + Pt) bilayers on a MgO(001) substrate at 650°C in vacuum are investigated. The synthesized composite films contain ferromagnetic CoPt grains with an average size of 25–45 nm enclosed in a nonconducting Al2O3 matrix. The saturation magnetization (Ms ~ 330 G) and coercivity (Hc ≈ 6 kOe) of the films are measured in the film plane and perpendicular to it. The obtained films are characterized by a spatial rotational magnetic anisotropy, which makes it possible to arbitrarily set the easy magnetization axis in the film plane or perpendicular to it using a magnetic field stronger than the coercivity (H > Hc).