非晶态(Fe_(1-x)Nb_x)_(84.5)B_(15.5)合金的磁性和热稳定性

MAGNETIC PROPERTIES AND THERMAL STABILITIES OF AMORPHOUS (Fe1-xNbx)84.5B15.5 ALLOYS

用单辊急冷法制备了非晶态(Fe_(1-X)Nb_X)84.5B_(15.5)(X=0,0.02,0.04,0.06,0.08,0.1)合金,测量了饱和磁化强度与温度的关系,得到居里温度T_o随Nb含量X的增加而线性下降,其递减率dT_o/dx=17.6K/at％Nb.计算出Nb含量对交换积分的涨落影响较小.用热磁测量和X光衍射的实验结果分析了晶化过程中的结构相变。晶化温度T_(cr)从x=0时的663K增加到x=0.1时的784K.由于Nb含量的加入T_(cr)。随合金的平均外层电子数e/a的下降而增加以及晶化过程中相变的复杂性是改善非晶态FeB合金热稳定性的主要因素.

The ribbons of amorphous (Fe1-aNba)84.5B15.5 (x=0,0.02, 0.04, 0.06, 0.08, 0.1) alloys were produced by melt spinning. The saturation magnetization at 12 K Oe were measured with magnetic balance in the temperature range of 77-1200 K. Experimental results show that the curie temperature, Tc, linearly diminishes with increasing Nb content of the alloy, the rate of which is about l7.6K/at% Nb. The effect of Nb on the fluctuation of the exchange integral is smaller than that of Mo. Crystalline phases are analysed using experimental results of thermomagnetization and X-ray diffraction. Tcr increases with Nb content from 663 K (x=0) to 784 K (x = 0.1). It is considered that the improvement of thermal stability is due to the increase of Tcr with diminishing average outer electron concentration, e/a, and due to the complexity of crystalline phases, when Fe is replaced by Nb in amorphous. FeB alloys.