Prediction of Interesting Ferromagnetism in Janus Semiconducting Cr2AsP Monolayer

Abstract

2D half-metallic materials that have sparked intense interest in advanced spintronic applications are essential to the developing next-generation nanospintronic devices. This study has adopted a first-principles calculation method to predict the magnetic properties of intrinsic, Se-doped, and biaxial strain tuning Cr₂AsP monolayer. The Janus Cr₂AsP monolayer is proven to be an intrinsic ferromagnetic (FM) semiconductor with an exchange splitting bandgap of 0.15 eV at the PBE+U level. Concentration-dependent Se doping, such as Cr₂As${}_{1-x}$Se_xP (x = 0.25, 0.50, 0.75), can regulate Cr₂AsP from FM semiconductor to FM half-metallicity. Specifically, the spin-up channel crosses the Fermi level, while the spin-down channel has a bandgap. More interestingly, the wide half-metallic bandgaps and spin bandgaps make them have important implications for the preparation of spintronic devices. At last, it also explore the effect of biaxial strain from -14% to 10% on the magnetism of the Cr₂AsP monolayer. There appears a transition from FM to antiferromagnetic (AFM) at a compressive strain of -10.7%, originating from the competition between the indirect FM superexchange interaction and the direct AFM interaction between the nearest neighboring Cr atoms. Additionally, when the compressive strain is -2% or the tensile strain is 6%, the semiconducting Cr₂AsP becomes a half-metallic material. These charming properties render the Janus Cr₂AsP monolayer with great potential for applications in spintronic devices.