Origins of coercivity in the amorphous alloy Nd-Fe-Al

摘要

Results obtained from detailed studies of the microstructure and devitrification behavior, as revealed by advanced electron micrsocopy and synchrotron x-ray diffraction techniques, were compared with magnetic and thermal analysis characterization to obtain insight into the appreciable- coercivity of nominally-amorphous melt-spun ribbon of Nd{sub}(60-(2/3x))Al{sub}(10+x) (-2 < x < 6.5). The as-spun microstructure consists of an amorphous Nd-rich, magnetically-soft matrix with clusters of approximate 1.2 nm diameter that apparently confer the hard magnetic properties to the alloy. The clusters are tentatively identified as sub-unit-cells of Nd{sub}6Fe{sub}(13-x)Al{sub}(1+x), by virtue of their unique and analogous temperature-dependent magnetic character as well as considerations of the ternary phase relationships during solidification.