Observing the Magnetization Distribution in the Pseudo Soft Underlayer of Perpendicular Magnetic Recording Media by Electron Holography

We visualized the magnetic flux density of the cross track direction in the pseudo soft underlayer (SUL) of perpendicular magnetic recording media. We deposited a pseudo-SUL on the fabricated slider of a perpendicular magnetic recording head, and used electron holography to visualize and quantify the magnetic flux magnitude and distribution in the pseudo-SUL. We observed the pseudo-SUL magnetized by the write field from the writer pole tip. The magnetic flux magnitude and full width at half maximum increased with an increasing write field. We observed a correspondence between an actual recording situation and the electron holography observation.