Magnetic Force Microscopy of Recording Heads

Magnetic force microscopy (MFM) images of a thin-film head and metal-in-gap (MIG) heads are presented. Results for the thin-film head show that it is possible to image a high-frequency magnetic field up to at least 50 MHz by using an iron-coated tip. MFM images of the MIG heads indicate intrinsic features such as the effect of the high saturation magnetic flux density of Sendust, a magnetic boundary at the interface of the Sendust and ferrite, electrical resonance, and a frequency limit beyond which these heads cannot excite magnetic fields. © 1991 IEEE