DOMAIN-STRUCTURES OF DIE-UPSET MELT-SPUN NDFEB

Domain patterns at the surface of thermally demagnetized MQIII, anisot ropic Nd2Fe14B permanent magnet produced by hot pressing and die-press ing and die-upsetting melt-spun ribbons have been obtained by Kerr mic roscopy. Patterns have been observed on surfaces perpendicular, parall el, and at an angle of approximately 25-degrees, to the direction of e asy magnetization. The magnetic domains are shown to have a mazelike s tructure on a scale of approximately 0.3-0.5 mum in the plane perpendi cular to the c axis. In the plane parallel to the c axis a much finer magnetic structure was observed. There is evidence that domains extend across the interfaces between neighboring ribbons.