材料期刊网

High-field magnetization behavior of (Nd,Pr)2Co14B compounds at T = 4.2 K has been studied through applying high fields up to 35 T. Taking the misalignment of grains in the samples into account, the anisotropy constants K1, K2, and K3 were determined by means of fitting the hard magnetization curves. Within the framework of the theory developed by Asti and Bolzoni, FOMP phenomena are predicted to occur in the whole system (0 < x < 1). Accompanying the transformation from easy cone (x = 0) to easy axis (x > 0.2), the type of FOMP changes from P1C to P1. The critical field of the FOMP transition increases with increasing Pr content. Magnetic measurements show that a valence instability of the Pr ion may exist.