  Two-dimensional (2D) ferromagnets have recently drawn extensive attention,
and here we study the electronic structure and magnetic properties of the bulk
and monolayer of CrSBr, using first-principles calculations and Monte Carlo
simulations. Our results show that bulk CrSBr is a magnetic semiconductor and
has the easy magnetization b-axis, hard c-axis, and intermediate a-axis. Thus,
the experimental triaxial magnetic anisotropy (MA) is well reproduced here, and
it is identified to be the joint effects of spin-orbit coupling (SOC) and
magnetic dipole-dipole interaction. We find that bulk CrSBr has a strong
ferromagnetic (FM) intralayer coupling but a marginal interlayer one. We also
study CrSBr monolayer in detail and find that the intralayer FM exchange
persists and the shape anisotropy has a more pronounced contribution to the MA.
Using the parameters of the FM exchange and the triaxial MA, our Monte Carlo
simulations show that CrSBr monolayer has Curie temperature Tc = 175 K.
Moreover, we find that a uniaxial tensile (compressive) strain along the a (b)
axis would further increase the Tc.

Materials Science;Strongly Correlated Electrons