Tunable electronic and magnetic properties of Cr2M′C2T2 (M′ = Ti or V; T = O, OH or F)

Here we report on the magnetic properties and electronic structures of Cr2M′C2T2 (M′ = Ti, or V; T = O, OH, or F) systems investigated by means of first-principles calculations. Results indicate that Cr2M′C2T2 can be nonmagnetic, anti-ferromagnetic, or ferromagnetic and either a semiconductor or metal depending on the choice of M′ and T and the through-bond coupling interactions that affect the arrangements of Cr2M′C2T2 systems. It was found that Cr2TiC2O2 is nonmagnetic, Cr2TiC2F2 and Cr2TiC2(OH)2 are anti-ferromagnetic. Cr2VC2(OH)2, Cr2VC2F2, and Cr2VC2O2 are ferromagnetic. The Curie temperatures of Cr2VC2(OH)2, Cr2VC2F2 are up to 618.36 and 695.65 K, respectively, calculated by the Heisenberg model with mean-field approximation. By using HSE06 methods, Cr2TiC2F2 was found to have an indirect band gap of approximately 1.35 eV while Cr2TiC(OH)2 was found to have a direct band gap of 0.84 eV. The tunable magnetic properties and electronic structures make the Cr2M′C2T2 (M′ = Ti, or V; T = O, OH, or F) double transition metal carbides promising two dimensional materials for applications in spin electronics, photocatalysis, and data storage.