Positron annihilation study of an Fe14Nd2B-type permanent magnet alloy (abstract)

Abstract

A Dy-substituted Fe14Nd2B-type permanent magnet alloy (Crumax 32) has been studied by positron annihilation lifetime spectroscopy, and also magnetic coercivity and microstructural analysis, to evaluate the effects of thermal treatment of the material. The results of this study show that the room temperature lifetime spectra can be modeled accurately using a partially constrained three-component fit. The variations in lifetime spectra induced by thermal treatment of the sintered magnet can be correlated with the concomitant decreases in coercivity and with a decrease in the surface area of free α-Fe as indicated by transmission electron microscopy.