Temperature dependence of the coercive force in Nd/sub 4/Fe/sub 77/B/sub 19/

The temperature dependence of the coercivity /sub J/H/sub c/ of Fe/sub 3/B-based Nd/sub 4/Fe/sub 77/B/sub 19/ permanent magnetic materials is analyzed. The coercivity of these melt-spun materials vanishes above the Curie temperature of the minor phase Nd/sub 2/Fe/sub 14/B. Nd/sub 4/Fe/sub 77/B/sub 19/ magnets also show a maximum in the /sub J/H/sub c/ versus T curve at low temperatures. The coercivity of these melt-spun materials has a smaller temperature coefficient than that of sintered Nd-rich NdFeB magnets. The relation of the observed T-dependence of /sub J/H/sub c/ to the anisotropy field of Nd/sub 2/Fe/sub 14/B is discussed.<
>