Thin films of barium ferrite with perpendicular magnetic anisotropy produced by laser ablation deposition

Barium ferrite thin films with perpendicular magnetic anisotropy have been prepared on heated (001) sapphire substrates by laser ablation deposition in an oxygen atmosphere using a KrF excimer laser. X-ray diffraction patterns reveal highly oriented films of the magnetoplumbite phase with a c-axis angular spread of 1.8°. Scanning electron micrographs reveal that these films are polycrystalline with a crystallite size of 0.4 μm. There is no surface particulate contamination. The saturation magnetization was similar to bulk barium ferrite, and the coercivity was 145 mT. The magneto-optical properties of the films are compared with those derived from the optical and magneto-optical constants of the bulk material.