Two-dimensional intrinsic ferromagnetic TiXY3 (X = Al, Ga; Y = S, Se, Te) monolayers with high Curie temperature from first principles

Abstract

The development of spintronic devices has been limited by the scarcity of intrinsic two-dimensional ferromagnetic materials. In this study, we predict a series of intrinsic ferromagnetic TiXY3 (X = Al, Ga; Y = S, Se, Te) monolayers. We systematically investigate their magnetic and electronic properties from first principles. Phonon spectra and ab initio molecular dynamics simulations confirm their dynamic and thermal stabilities. All TiXY3 monolayers exhibit ferromagnetic ground states and possess magnetic easy axes along the out-of-plane direction, with the TiGaSe3 monolayer achieving an magnetic anisotropy energy of 1.574 meV. Notably, these materials have strong magnetic coupling, which is calculated by the first-principles linear response method. Monte Carlo simulation results indicate that the Curie temperatures (TC) of these monolayers are close to or significantly exceed room temperature. Especially, the TC of the TiAlSe3 monolayer reaches 792 K. Our study indicates that TiXY3 monolayers with high Curie temperature are promising candidates for spintronic device applications.