Two-dimensional magnetic order in Cr-based transition metal chalcogenides

Long-range ferromagnetic order in the single-layer limit appears to be possible in several chromium-based chalcogenides and halides with layered structure. Ab initio calculations based on the density functional theory of different Cr-based chalcogenides are analyzed approaching the two-dimensional limit. The focus will be on magneto-crystalline anisotropy and how to obtain an out-of-plane magnetic polarization that would help circumvent the restrictions of the Mermin-Wagner theorem. This will be studied through various means like strain, pressure, the stability of charge density waves (CDW)[1], stoichiometry and other different structural details. The electronic structure of these compounds will be discussed as an approach to the understanding of the magnetic properties of the transition metal chalcogenide family in general.

[1] Adolfo O. Fumega, Jan Phillips, Victor Pardo, “Controlled two-dimensional ferromagnetism in 1T-CrTe₂: the role of charge density wave and strain”, J. Phys. Chem. C 124, 21047 (2020).