Fe‐ and Co‐Doped Tungsten Disulfide Monolayers: 2D Ferromagnetic Half‐Metals at Room Temperature

Abstract

2D ferromagnetic (FM) materials are rare at room temperature. In situ substitution of magnetic atoms may be a promising method to induce magnetism in nonmagnetic materials. Herein, the magnetism in Fe‐ and Co‐doped WS2 (Fe:WS2 and Co:WS2 ) monolayers by using density functional theory is studied. The Fe and Co atoms substitute the W atoms with a relatively large doping concentration (16.7%), respectively. Both doped monolayers are FM half‐metals with the out‐of‐plane easy magnetization axis. The estimated Curie temperature can be up to about 540 K in Fe:WS2 and 370 K in Co:WS2. Moreover, the magnetic anisotropic energy in Fe:WS2 can be larger than 16 meV cell−1 under −4% compressive strain. Although compressive strain leads to a higher Curie temperature in Co:WS2, it slightly reduces the Curie temperature in Fe:WS2 due to the enhanced anti‐FM coupling of next nearest‐neighboring exchange interaction. It is suggested by the calculations that both Fe:WS2 and Co:WS2 monolayers are 2D FM half‐metals at room temperature, which may be promising candidates in nanoscale spintronic devices.