Emerging Half-Metallic Property in the Kagome Lattice Ti3Te5 Monolayer

Two-dimensional materials with intrinsic magnetism have provoked comprehensive attention due to their potential application in spintronics. In this work, based on density functional theory calculations, we report two stable Kagome latticed monolayers, Ti3X5 (X = Te, Bi), consisting of three titanium atoms and five Te (Bi) atoms per unit cell, with intrinsic magnetism and out-of-plane magnetic easy axis. Both Ti3X5 systems are found to have high thermodynamical and mechanical stability; meanwhile, they exhibit mechanical isotropy reflected by Young's modulus and Poisson's ratio. Spin-polarized calculations show that the Ti3Te5 monolayer is a robust ferromagnetic (FM) half-metal (HM) with the respective Curie temperature (TC) of 72 K, while the Ti3Bi5 monolayer is an antiferromagnetic (AFM) metal with Néel temperatures (TN) as high as 132 K. Furthermore, the magnetism of the Ti3Te5 monolayer is found to be sensitive to the external strains, in which the FM HM to AFM metal transition occurs when applying 2% compressive strain. Interestingly, the out-of-plane to in-plane magnetic easy axis transition and higher than room temperature TC are achieved from 3% to 6% tensile strains. Our results may provide new clues for searching and designing two-dimensional room temperature FM half-metals.