Abnormal temperature dependence of intrinsic coercivity in sintered Sm–Co-based permanent magnets.

Autor: Liu, Sam, Yang, Jie, Doyle, George, Potts, Gregory, Kuhl, G. Edward
Předmět:
Zdroj: Journal of Applied Physics; 5/1/2000, Vol. 87 Issue 9, p6728, 3p, 4 Graphs
Abstrakt: In search of high-temperature permanent magnet materials, sintered Sm–Co-based magnets with abnormal temperature dependence of intrinsic coercivity have been obtained. These magnets have small negative, or near-zero, or large positive temperature coefficients of intrinsic coercivity. A model of coercivity mechanism has been proposed to explain this abnormal temperature dependence. According to this model, the coercivity in 2:17-type permanent magnets is controlled by two conflicting mechanisms. The first mechanism is thermal activation, which leads to decreased coercivity with increasing temperature. The second mechanism can be explained by a pinning process in which increasing temperature may result in an increased difference of crystalline anisotropy between the 2:17 cell phase and 1:5 cell boundary phase and, in turn, a higher coercivity at high temperature. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]
Databáze: Complementary Index