Perpendicular Anisotropy Master Medium in Magnetic Printing for Writing High-Density Servo Signal

A perpendicular anisotropy master medium (PAMM) has been proposed for magnetic printing, and it is expected to improve the printing characteristics of the servo signal. In this study, we experimentally performed magnetic printing by using the PAMM, which is composed of CoPt magnetic film, with perpendicular magnetic anisotropy and large saturation magnetization. It is clarified that the optimum printing field for PAMM is 3.5 kOe, which is 0.5 kOe lower than that of conventional master medium, and that the output signal from the slave medium printed by PAMM is about twice larger than that of the conventional master medium. Furthermore, the printing characteristics for PAMM can be further improved with thicker magnetic film.