Enhanced Curie temperature in partially decorated CrSnSe monolayer with alkali metals (Li, Na, and K).

A two-dimensional ferromagnetic layer with a large Curie temperature is highly desired for spintronics applications. Herein, we investigated the effect of the partial decoration of the CrSnSe monolayer with alkali metals Li, Na, and K on the structure, electronic and magnetic properties. The calculated formation energy, phonon dispersion curves, and molecular dynamics indicated that the decorated CrSnSe layers are stable and can be fabricated. The Li, Na, and K decorated systems display semiconducting band features, with bandgaps of 0.53, 0.55, and 0.55 eV, respectively, with the HSE06 hybrid functional. We found a ferromagnetic ground state and an in-plane magnetic anisotropy of -2.12, -2.42, and -2.39 meV per cell in the Li, Na, and K-decorated systems, respectively. Based on Monte Carlo Simulations, we obtained largely enhanced Curie temperatures of 241, 256, and 265 K in the Li, Na, and K decorated systems, respectively. Our findings suggest that the decorated layers could be used as potential candidates for spintronics applications.