Local magnetic structure and magnetic properties of Nd{sub}50Fe{sub}40Si{sub}(10-x)Al{sub}x bulk glassy

摘要

The large values over 300 kA/m at room temperature were found for the coercive field of Nd{sub}(50)Fe{sub}(40)Si{sub}(10-X)AL{sub}x (x = 0; 10) amorphous melt-spun ribbons and cast rods. The dependence of the coercive field on the thickness and the preparation method, namely the cooling rate, is ascribed to the existence in the amorphous matrix of very small ferromagnetic clusters, which approach of a single magnetic domain Coercivity increases substantially up to 600 kA/m by decreasing the temperature down to 200 K, although the measurements are carried out in low fields (up to 800 kA/m). The Mossbauer spectra can be fitted to two Fe sites with magnetic moments ranging from 1.25 to 2.20 μB depending on the additional element.