HIGH-FIELD MAGNETIZATION IN HO1-XERXGA2 SINGLE-CRYSTALS

The hexagonal antiferromagnetic compounds HoGa2 and ErGa2 exhibit larg e anisotropy with two metamagnetic-like transitions in external magnet ic fields applied along the easy direction: at 1.7 and 2.4 T along the alpha-axis for HoGa2, and at 0.7 and 2.0 T along the c-axis for ErGa2 . Magnetization measurements in high fields up to 40 T have been perfo rmed on single crystals of the substituted compounds Ho1-xErxGa2 (x = 0, 0.2, 0.4 and 0.6). In HoGa2, above the metamagnetic transition fiel ds, the a-axis magnetic moment increases slowly and reaches the value of 9.75 mu(B) at 40 T, whereas along the c-axis it sharply rises but t o a much lower value, of 7 mu(B) only. In substituted compounds, besid es the c-axis transition around 6 T, an additional transition appears at 18-19 T along the alpha-axis. The transition-field values were foun d to decrease slightly with increasing Er content for both transitions .