A promising robust intrinsic half-metallic MXene nanosheet Cr2CuC2 with high Curie temperature

Abstract

Two-dimension half-metallic ferromagnets are promising in spintronics. In recent years, the half-metallicity and the magnetic properties of the MXene materials have been research hotspots of new materials due to their unique crystal characteristics and wide promising applications. A new promising robust intrinsic half-metallic MXene nanosheet Cr2CuC2 with high Curie temperature (evidently above the room temperature) was predicted from the first principles calculations. The magnetic moment of this nanosheet is calculated as 5.00 μB per unit. Its half-metallic character and the magnetic moment mainly origin from the spin-polarized Cr-ions induced by the crystal field. With increase of the biaxial tensile strain on this nanosheet, its magnetic moment per unit remains 5.00 μB well. More importantly, its energy gap of the spin-down subband and the half-metallic energy gap both increase with the tensile strain, implying that the half-metallicity of this nanosheet may be evidently improved by the biaxial tensile strain. Charge state may cause important influence on the magnetic and electric properties of this nanosheet. If an electron is removed from this nanosheet, its magnetic moment per unit decreases from 5.00 μB to 4.00 μB, while its half-metallic character remains well. These magnetic moments per unit of this nanosheet before/after an electron is removed accord well to those analyzed by the two-center molecular orbital theory.