Domain-wall curvature and coercivity in pinning type Sm–Co magnets

Authors

Ralph Skomski, University of Nebraska-LincolnFollow

Document Type

Article

Date of this Version

April 1997

Comments

Published by Am Inst of Physics. J. Appl. Phys. 81 (1997) 5627-5629. Copyright 1997. Permission to use. http://www.aip.org/.

Abstract

The origin of coercivity in precipitation hardened Sm–Co magnets is investigated. By considering domain-wall pinning at boundary phase and Z phase inhomogenities, it is found that the hexagonal Z phase has no direct influence on the coercivity. The intuitive assumption of plane domain walls made in a recent calculation is unrealistic but has no direct effect on the coercivity. However, due to the comparatively large size of the 12:17 cells, the calculated three dimensional domain-wall curvature is sufficiently large to assure a nearly ideal nestling of the domain walls to the 1:5 cell boundary. This nestling yields a coercivity increase from about 0.1 to about 1 T and is therefore responsible for the high coercivity of 2:17 based Sm–Co magnets. © 1997 American Institute of Physics.