The magnetization reversal processes for L 10 -FePt (001) particulate films before and after Ar ion irradiation were experimentally investigated, and the size of the defect region (2 r0) and the effective demagnetization factor (Neff) were evaluated based on a phenomenological analysis. A large coercivity (Hc) of 30.4 kOe, which originates from the particulate structure, drastically reduced after ion irradiation. The phenomenological analysis showed the increase of 2 r0 by irradiating Ar ions, which clearly indicates that Hc is closely related with the size of 2 r0. In addition, the FePt particulate films show large Neff, which may arise from the large dipole interaction between particles and the distribution of particle sizes and shapes.
ASJC Scopus subject areas
- Physics and Astronomy(all)