Microstructure, domain walls, and magnetization reversal in hot-pressed Nd-Fe-B magnets

Transmission electron microscopy study of hot-pressed and hot-deformed Nd0.14(Fe0.94B0.06)0.86 magnets shows that the magnetic alignment is achieved by the formation of a microstructure consisting of platelets of Nd2Fe14B grains with the c axis normal to the platelet surface and parallel to the press direction. Magnetic domain walls, lying parallel to the c axis, run through many grains and are pinned at the intergranular phases that are produced during processing. Magnetization reversal occurs by domain wall motion.