Real picture of magnetic domain dynamics along the magnetic hysteresis curve inside an advanced permanent magnet

Abstract In the long history of permanent magnet research for more than 100 years, three-dimensional magnetic microscopy has been eagerly awaited to elucidate origin hysteresis magnets. this study, we succeeded in observing domain structure an advanced high-coercivity Nd-Fe-B-based throughout curve using a recently developed hard X-ray tomography technique. Focused-ion-beam-based scanning electron was employed study relationship between observed domains and microstructure same volume. Thermally demagnetized coercivity states exhibit considerably different structures but show periodicity 2.3 μm, indicating that characteristic length is independent magnetization states. Further careful examination revealed some unexpected behaviors, such as running perpendicular easy axis reversing back against field. These findings demonstrate wide variety real behaviors along inside magnet.