Angular-dependent remanent magnetization curve for perpendicular magnetic recording media determined by precise polar-Kerr detection system

We developed the polar-Kerr detection system and evaluated the angular dependence of magnetization curves with applied field of various directions during the newly developed system. The polar-Kerr detection system enabled precise evaluation of angular dependence of remanent coercivity ( H_cr), as compared with the conventional VSM system. In addition, a cusp appeared in polar-Kerr hysteresis loop was observed to originate magnetization reversal by the thermal agitation.