  Exploring the physics of low-dimensional spin systems and their
pressure-driven electronic and magnetic transitions are thriving research field
in modern condensed matter physics. In this context, recently antiferromagnetic
Cr-based compounds such as CrI3, CrBr3, CrGeTe3 have been investigated
experimentally and theoretically for their possible spintronics applications.
Motivated by the fundamental and industrial importance of these materials, we
theoretically studied the electronic and magnetic properties of a relatively
less explored Cr-based chalcogenide, namely LaCrS3 where 2D layers of magnetic
Cr3+ ions form a rectangular lattice. We employed density functional theory +
Hubbard U approach in conjunction with constrained random-phase approximation
(cRPA) where the later was used to estimate the strength of U. Our findings at
ambient pressure show that the system exhibits semiconducting antiferromagnetic
ground state with a gap of 0.5 eV and large Cr moments that corresponds to
nominal S=3/2 spin-state. The 1st nearest neighbor (NN) interatomic exchange
coupling (J1) is found to be strongly antiferromagnetic (AFM), while 2nd NN
couplings are relatively weaker ferromagnetic (FM), making this system a
candidate for 1D non-frustrated antiferromagnetic spin-chain family of
materials. Based on orbital resolved interactions, we demonstrated the reason
behind two different types of interactions among 1st and 2nd NN despite their
very similar bond lengths. We observe a significant spin-orbit coupling effect,
giving rise to a finite magneto crystalline anisotropy, and
Dzyaloshinskii-Moriya (DM) interaction. Further, we found that by applying
uniaxial tensile strain along crystallographic a and b-axis, LaCrS3 exhibits a
magnetic transition to a semi-conducting FM ground state, while compression
gives rise to the realization of novel gapless semiconducting antiferromagnetic
ground state.
