Enhanced perpendicular magnetic anisotropy energy and Curie temperature in the CrOCl monolayer: strain effects

Abstract Magnetic monolayers offer a wide variety of applications in enhancing the functionalities of storage devices including higher thermal stability, lower power consumption, and higher operation speed, owing to their intrinsic long-range spin ordering. Herein, we study the biaxial ([110]) strain range of ± 5% influence on the formation energetics, and electronic, and magnetic properties of the CrOCl monolayer (ML) based on the first-principles calculations including spin-orbit coupling (SOC) effects. It is predicted that the unstrained system is an insulator having an energy band gap (Eg) of 2.05 eV with a ferromagnetic (FM) ground state. The computed partial spin magnetic moment on the Cr ion is +2.7 µB/f.u. (per formula unit) with S = 1.5 and lies in a +3 state with an electronic distribution of t32g ↑ t20g ↓ eg0 ↑ eg0 ↓. Along with this, [001] (c-axis) is found to be the easy magnetic axis, which results in a magnetic anisotropy energy (MAE) of 0.2 meV having an MAE constant of 0.25 mJ/m2 and the estimated Curie temperature (Tc) using Ising model is 157 K. Furthermore, the system shows the robustness of the FM insulating behavior against considered strained. However, a well-ordered shift in the conduction band edge position to lower energies is predicted for tensile strains, which substantially reduces the Eg up to 13%. The decrease in Eg value is evidence of higher absorption in the visible range which makes it the best option for optoelectronics and photocatalysis. Simultaneously, Simultaneously, our results revealed that strain enhances the MAE and Tc up to 190% and 43%, respectively. Hence, optimized Eg, MAE, and Tc within a considerable strain range, make the CrOCl ML a potential candidate for its make the CrOCl ML a potential candidate for its utilization in magnetic memory devices.