Abstract
The magnetization M of single crystalline TmB4 has been investigated in high magnetic fields up to 54 T and shows considerably anisotropic behavior. In the ordered antiferromagnetic state, the M for B ∥ [001] reaches the saturation magnetization Ms at about 4 T accompanying with plateaux at 1/8 Ms and 1/2 Ms. On the other hand, for B ∥ [100] and [110], the 1/2 Ms state and the saturation of Mwere observed at much higher field above 30 T. The results are discussed in relation to the effects of magnetic frustration and the crystalline electric field.