Recent Progress in Research on Ferromagnetic Rhenium Disulfide.

Since long-range magnetic ordering was observed in pristine Cr 2 Ge 2 Te 6 and monolayer CrCl 3 , two-dimensional (2D) magnetic materials have gradually become an emerging field of interest. However, it is challenging to induce and modulate magnetism in non-magnetic (NM) materials such as rhenium disulfide (ReS 2 ). Theoretical research shows that defects, doping, strain, particular phase, and domain engineering may facilitate the creation of magnetic ordering in the ReS 2 system. These predictions have, to a large extent, stimulated experimental efforts in the field. Herein, we summarize the recent progress on ferromagnetism (FM) in ReS 2 . We compare the proposed methods to introduce and modulate magnetism in ReS 2 , some of which have made great experimental breakthroughs. Experimentally, only a few ReS 2 materials exhibit room-temperature long-range ferromagnetic order. In addition, the superexchange interaction may cause weak ferromagnetic coupling between neighboring trimers. We also present a few potential research directions for the future, and we finally conclude that a deep and thorough understanding of the origin of FM with and without strain is very important for the development of basic research and practical applications.