Strain‐Induced Magnetism in MSi<sub>2</sub>N<sub>4</sub> (M = V, Cr): A First‐Principles Study
Yingmei Li, Jing Wang, Guochun Yang, Yong Liu
Abstract
Abstract The discovery of ferromagnetic 2D van der Waals (vdW) materials has opened up opportunities for exploring and harnessing magnetism in low‐dimensional limit, and developing innovative paper‐like spintronic devices. Stress engineering demonstrates unique advantages in regulating material properties, especially for 2D materials. With the aid of first‐principles calculations, the effectiveness of strain engineering for modulating the electronic and magnetic properties of MSi 2 N 4 (M = V, Cr) monolayers from a new family of layer‐structured 2D vdW materials is explored. Their magnetic configurations are effectively tuned via the uniaxial and biaxial tensile strain of in‐plane lattice vectors. VSi 2 N 4 exhibits half‐metallic ferromagnetic character, whereas CrSi 2 N 4 is prone to be antiferromagnetic (AFM), which is rationalized from the competition between the direct metal–metal AFM interaction and the 90 0 ferromagnetic superexchange. More intriguingly, VSi 2 N 4 demonstrates a high magnetic ordering temperature of 285 K, which is close to room temperature. The predicted appealing properties of VSi 2 N 4 under strain await experimental confirmation.