Magnetization studies in CoHoB amorphous alloys

Amorphous Co 80-x Ho x B 20 alloys have been prepared by melt spinning technique and their magnetization measured in applied fields up to 80 kOe. The saturation is obtained for H ≤ 30 kOe at all temperatures. The projection of the Ho moment at 4 K is found to be 10.2 ± 0.5 μ B in agreement with the theoretical value. This would indicate a collinear spin structure for Ho unlike for Er. It can be concluded that the antiferromagnetic interaction J CoHo is stronger than the random anisotropy. For x= 11.5 at 4 K, the Ho sub-network moment dominates.