Microstructural evolution and magnetization reversal mechanism of CoPt films with perpendicular magnetic anisotropy

Microstructural evolution and magnetization reversal mechanisms of perpendicular magnetic anisotropic Co72Pt28 films were investigated. Results showed that in the initial stage of film growth, the Co72Pt28 film was continuous and followed a dome-shaped structure with increasing film thickness. When the film thickness further increased above a certain critical value, the film growth acquired an inverted frustum shape structure and increased the intergranular magnetic interaction. The magnetization reversal mechanism showed a strong dependence on microstructures. The magnetization reversal followed the domain wall motion behaviour when the film was continuous and deviated towards the Stoner-Wohlfarth (S-W) model in the dome-shaped regime. A further deviation away from the S-W model was observed, when the film acquired an inverted frustum shape structure in order to minimize the surface energy.