DFT Study of Magnetic Properties of Layered TlGaS2-Fe

This work presents a first-principles investigation of the magnetic and electronic properties of Fe-doped layered TlGaS₂ using density functional theory (DFT) within the DFT+U framework. The calculations were performed using the spin-polarized generalized gradient approximation (SGGA) with an effective Hubbard parameter of U = 6 eV applied to Fe 3d orbitals to properly account for strong electron–electron correlations. Pristine TlGaS₂ crystallizes in a monoclinic structure with space group C2/c (No. 15) and exhibits semiconducting behavior. Substitutional doping of Fe at the Ga site induces magnetism in the system, leading to the formation of a diluted magnetic semiconductor. The total magnetic moment of the TlGaS₂–Fe system is found to originate predominantly from localized Fe 3d states, with additional contributions from neighboring sulfur atoms due to p–d hybridization. A 32-atom supercell model was employed to analyze the spin density distribution, magnetic moments, and electronic structure. The calculated total magnetic moment reaches approximately 5.0 μB per supercell, with the Fe atom contributing about 3.76 μB. The influence of the local atomic environment on magnetization was examined, revealing that sulfur atoms in the immediate vicinity of the Fe impurity play a significant role in enhancing the magnetic response, while the contributions from Tl and Ga atoms remain negligible. Electronic band structure and density of states analyses demonstrate that Fe doping modifies the electronic structure of TlGaS₂, driving the system toward metallic or half-metallic behavior depending on spin polarization. These findings indicate that Fe-doped TlGaS₂ is a promising two-dimensional magnetic material with potential applications in spintronics, spin injection, and magnetic memory devices. This dataset and manuscript provide theoretical insight that can guide future experimental studies and the design of functional magnetic 2D materials based on layered chalcogenides.