Coercive force of new Cu-substituted samarium cobalt alloys

Abstract

It was found that sintered alloys having a composition of approximately z=8 in Sm(Co_0.85Fe_0.05Cu_0.10)_z exhibit a high coercive force on the order of 10 kOe, for 5–10‐μm average grain size. Magnetization and demagnetization curves showed that the coercive force is controlled by a nucleation process. Attempts were made to achieve a high density without serious grain growth by means of high‐pressure isostatic compaction and hot pressing, resulting in 96% of the density and 7‐μm average grain size. With this approach, B_r=10.3kG, _IH_c=10.2 kOe, and a maximum energy product of 22.0 MG Oe were achieved.