A DFT investigation of electronic, magnetic, and optical properties of 2D MFeCl6 (M= Zr, Hf) single-layer

The 2D MFeCl₆ (M = Zr, Hf) single layer has attracted much interest due to its featured properties, which have been studied using density functional theory (DFT). Calculations employing different DFT approaches, including DFT, DFT + SOC, DFT + U, and HSE, consistently showed that these compounds are indirect band gap semiconductors. A ferromagnetic (FM) characteristic was observed, exhibiting a range of total magnetic moments from 3.8 μB to 7.6 μB, largely originating from the Fe-3d orbitals. On the other hand, optical characteristics are studied by achieving the dielectric functions, energy loss functions, reflectance spectrum, and absorption coefficients. Furthermore, a correlation between electronic and optical properties is established through orbital hybridization in the Zr-Cl, Hf-Cl, and Fe-Cl bonds. Consequently, the outstanding properties of these materials suggest strong potential applications in electronic, optoelectronic, and spintronic devices.