2D robust intrinsic ferromagnetic half-metals Cr2XP with high Curie temperature

• Monolayer Cr 2 XP (X=S, Se, Te) are predicted to be robust intrinsic ferromagnetic half-metals. • Half-metallic gaps of Cr 2 XP (X=S, Se, Te) are 1.24, 1.35 and 1.40 eV. • Curie temperatures of monolayer Cr 2 XP (X=S, Se, Te) are 660, 810 and 720 K. • The total magnetic moments of Cr 2 XP (X=S, Se, Te) are about 7 µ B . 2D intrinsic ferromagnetic half-metals have received extensive attention for their promising application in spintronic devices. However, according to the Mermin-Wagner theorem, their Curie temperature hardly exceeds room temperature. Furthermore, a small half-metallic gap also limits their application in room-temperature environments. Through the first-principles and Monte Carlo calculations, we design a family of 2D room-temperature intrinsic ferromagnetic half-metals Cr 2 X P ( X =S, Se, Te) with large magnetization, high Curie temperatures (>660 K), sizable half-metallic gap and good structural stability. Their large magnetic moments ∼ 7µ B arise from the exchange splitting of Cr- d orbital in the D 4h crystal field, and the ferromagnetic coupling is derived from the Cr-P-Cr super-exchange interaction mediated by P atom, the origin of wide half-metallic gap (>1.24 eV) is briefly from the exchange splitting of d xy and d xz / d yz orbitals. In addition, the Cr 2 SP and Cr 2 SeP show the out-of-plane magnetocrystalline anisotropy energies (MAEs) of 188.25 and 46.57 µeV/f.u., and the Cr 2 TeP possess an in-plane MAE of 329.01 µeV/f.u. These intriguing advantages make the Cr 2 X P as an attractive candidate for spintronic devices.