Abstract
The magnetic properties of several amorphous alloys prepared by melt spinning have been studied. These comprise alloys of the series Tb1−xCox, Y1−xCox (0.25⩽x⩽0.60), and R69Co31 (R=La, Nd, Sm, Gd, Tb, Dy, Ho, and Er). Most of the alloys in which the R component has an orbital momentum were found to exhibit large intrinsic coercive forces at low temperatures. The thermomagnetic history effects studied on several of these alloys have been interpreted in terms of a thermally activated magnetization process. The magnetic ordering temperatures of the series R69Co31 scale to the deGennes factor (g−1)2J(J+1) only approximatley. The systematic deviations suggest that the indirect magnetic coupling between the localized 4 f moments involves a term proportional to Si⋅Lj in addition to the main term, proportional to Si⋅Sj .