Paramagnetic phases of two-dimensional magnetic materials

Abstract

The magnetic long-range ordering states of van der Waals magnets at low temperatures have gained much interest, yet their high-temperature paramagnetic states remain largely unexplored. In this paper, we apply the disordered local moment picture for describing the paramagnetic states of two-dimensional magnetic semiconductors. We calculate the electronic structure of paramagnetic phases of ${\mathrm{CrI}}_{3},\phantom{\rule{0.28em}{0ex}}{\mathrm{CrSiTe}}_{3}$, and ${\mathrm{NiPS}}_{3}$ using the density functional theory with static Hubbard corrections. The semiconducting electronic structures are successfully reproduced without any inclusion of dynamical correlation effects. The local electronic structure of magnetic ions in the paramagnetic phase resembles those in the magnetically ordered phase. The band structures of the paramagnetic phases are also analyzed. The itinerant ferromagnet ${\mathrm{Fe}}_{3}{\mathrm{GeTe}}_{2}$ is also briefly discussed where the disordered local moment picture is not applicable due to the coexistence of itinerant and local magnetism.