MAGNETIZATION REVERSAL MECHANISM EVALUATED BY ROTATIONAL HYSTERESIS LOSS ANALYSIS FOR THE THIN-FILM MEDIA

In the present study. rotational hysteresis loss analysis is carried out for CoCrTa, CoNiPt and CoCrPt thin film media to evaluate the influence of microstructure on coercive force through the measurement of magnetic anisotropy. In each media, the magnitudes of H(k)grain defined as a magnetic field where rotational hysteresis loss W(r) diminishes remain almost a constant value independently of the values of coercive force. With increasing coercive force, the magnitude of coercive force gradually becomes smaller than that of switching field of magnetization H(p) evaluated by torque analysis. Through the analysis of H(k)grain and H(p), it is suggested that the coercive force in each examined media is strongly dependent on the degree of intergranular exchange coupling and/or magnetostatic interactions. While, in CoNiPt and CoCrPt media, coercive force has a dependence on rotational hysteresis integral R(h), however, in CoCrTa films, any correlation between them was not observed.