TaF 4 : A Novel Two-Dimensional Antiferromagnetic Material with a High Néel Temperature Investigated Using First-Principles Calculations.

The structural, electronic, and magnetic properties of a novel two-dimensional monolayer material, TaF 4 , are investigated using first-principles calculations. The dynamical and thermal stabilities of two-dimensional monolayer TaF 4 were confirmed using its phonon dispersion spectrum and molecular dynamics calculations. The band structure obtained via the high-accuracy HSE06 (Heyd-Scuseria-Ernzerhof 2006) functional theory revealed that monolayer two-dimensional TaF 4 is an indirect bandgap semiconductor with a bandgap width of 2.58 eV. By extracting the exchange interaction intensities and magnetocrystalline anisotropy energy in a J 1 - J 2 - J 3 - K Heisenberg model, it was found that two-dimensional monolayer TaF 4 possesses a Néel-type antiferromagnetic ground state and has a relatively high Néel temperature (208 K) and strong magnetocrystalline anisotropy energy (2.06 meV). These results are verified via the magnon spectrum.