Study on Magnetization Reversal of Perpendicular Recording Media by In-Field MFM Observation

Magnetization reversal is a crucial issue to reduce a medium noise in high-density perpendicular magnetic recording. The magnetization reversal behaviors govern the writing process, zigzag transition boundary, transition jitter, and thermal stability. However, up to now, few works have been devoted to reveal magnetization behaviors by in situ MFM observation under magnetic fields, which is an extremely important issue to improvement of recording media. In this work, in-situ MFM observations were performed under various magnetic fields to make clear the magnetization reversal process microscopically. The activation volume in media was estimated by the magnetization reversal field map (MRF-map) technique, and the magnetization processes was discussed.