Studies on high data rate perpendicular heads are presented in this work. Ferromagnetic resonance (FMR) was observed for these heads using an impedance measurement technique [X. Xing et al, IEEE Trans. Magn. 43, 2181 (2007)]. From the measured FMR frequency, the effective in plane stiffness of the yoke can be determined. An external field was also applied parallel to the easy axis of the yoke to manipulate the effective in plane stiffness. As external field increases, a higher FMR frequency is observed and the head frequency response improves due to the increased stiffness of the write head. The result indicates that the FMR of the yoke becomes a more important limiting factor of the head switching dynamics.
展开▼
