Strain-induced electronic and magnetic transition in the $S=\frac{3}{2}$ antiferromagnetic spin chain compound ${\mathrm{LaCrS}}_3$

Exploring the physics of low-dimensional spin systems and their pressure-driven electronic and magnetic transitions is a thriving research field in modern condensed matter physics. In this context, recently antiferromagnetic Cr-based compounds such as ${\mathrm{CrI}}_3$, ${\mathrm{CrBr}}_3$, and ${\mathrm{CrGeTe}}_3$ 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 ${\mathrm{LaCrS}}_3$, where two-dimensional (2D) layers of magnetic ${\mathrm{Cr}}^{3+}$ ions form a rectangular lattice. We employed density functional theory $+$ Hubbard $U$ approach in conjunction with constrained random-phase approximation, where the latter was used to estimate the strength of $U$. Our findings at ambient pressure show that the system exhibits a semiconducting antiferromagnetic ground state with a gap of 0.5 eV and large Cr moments that correspond to a nominal $S=3/2$ spin state. The first nearest neighbor (NN) interatomic exchange coupling $\left(J_1\right)$ is found to be strongly antiferromagnetic, while the second NN couplings are relatively weaker ferromagnetic (FM), making this system a candidate for a 1D nonfrustrated antiferromagnetic spin-chain family of materials. Based on orbital resolved interactions, we demonstrated the reason behind two different types of interactions among first and second NNs despite their very similar bond lengths. We observe a significant spin-orbit coupling effect, giving rise to a finite magnetocrystalline anisotropy, and Dzyaloshinskii-Moriya interaction. Further, we found that by applying uniaxial tensile strain along the crystallographic $a$ and $b$ axis, ${\mathrm{LaCrS}}_3$ exhibits a magnetic transition to a semiconducting FM ground state, while compression gives rise to the realization of a gapless semiconducting antiferromagnetic ground state. Thus our findings can enrich the versatility of ${\mathrm{LaCrS}}_3$ and make it a promising candidate for industrial applications.