Magnetic anisotropy of tetragonal rare-earth compounds RRu_2Al_2B (R: Rare-earth metals)

摘要

Recently, a new tetragonal compound CeRu_2Al_2B, which shows successive magnetic transitions of antiferromagnetic and ferromagnetic orders was discovered. In this paper, the results of magnetization measurements on magnetically-aligned powder sample of CeRu_2Al_2B were reported. Highly-anisotropic behaviors between the magnetizations along the easy and the hard directions were observed. The anisotropic behavior of the magnetizations could be explained qualitatively by considering the crystalline-electric-field scheme with the Γ_7 (1) doublet ground state estimated from the previous nuclear magnetic resonance experiments. These results support the Ising-type ferromagnetic structure along the c-axis.