Highly anisotropic magnetic phase diagram of the ferromagnetic rare-earth diboride
Phys. Rev. B 112, 024423 – Published 14 July, 2025
DOI: https://doi.org/10.1103/ps2l-c434
Abstract
Rare-earth (RE) compounds have been of enormous interest in condensed matter physics as a platform for the exploration of interesting physical phenomena. Here, we report the successful single-crystal growth of , which exhibits a paramagnetic (PM)-ferromagnetic (FM) phase transition at 15 K and another phase transition at 11 K, and the discovery of a highly anisotropic magnetic phase diagram of this FM diboride. Magnetization measurements suggest that the ferromagnetically ordered moments of ions are oriented at a direction tilted by 50° from the plane at 2 K, and they rotate largely toward the -plane direction upon application of a magnetic field but hardly toward the -axis direction. Heat capacity and electrical resistivity measurements clearly demonstrate that the low-temperature phase transition at 11 K occurs even under high magnetic fields along the -plane direction, whereas it disappears immediately by magnetic fields along the -axis direction. Moreover, the field-induced crossover phenomenon between FM and PM phases is found to be more promoted when applying a magnetic field along the -plane direction. The resulting magnetic phase diagram reveals that in-plane magnetic anisotropy is predominant in the present system, which contradicts the previous report of a spin-reorientation phenomenon toward the -axis direction between 11 and 15 K. Taken together, the present findings suggest the presence of strong competition between in-plane and out-of-plane magnetic anisotropies in , giving rise to the unique FM spin arrangement.
