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

Abstract

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 Cr2XP (X=S, Se, Te) with large magnetization, high Curie temperatures (>660 K), sizable half-metallic gap and good structural stability. Their large magnetic moments ∼ 7µB arise from the exchange splitting of Cr-d orbital in the D4h 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 dxy and dxz/dyz orbitals. In addition, the Cr2SP and Cr2SeP show the out-of-plane magnetocrystalline anisotropy energies (MAEs) of 188.25 and 46.57 µeV/f.u., and the Cr2TeP possess an in-plane MAE of 329.01 µeV/f.u. These intriguing advantages make the Cr2XP as an attractive candidate for spintronic devices.

Keywords

• 2D ferromagnetic half-metal
• First-principles and Monte Carlo calculations
• Electronic structure
• Magnetic properties