Itinerant Semiconducting Antiferromagnetism in Metastable V3Ga

Abstract

Herein, a metastable phase of β‐W type V3Ga is identified to exhibit an itinerant semiconducting antiferromagnetism. Density functional theory plus Hubbard U (DFT+U) calculations predict the β‐W type structure as a possible metastable phase, although energetically less favorable than the previously known D03 phase, which is successfully synthesized with good crystallinity by alternating evaporation method with postannealing process rather than traditional coevaporation method. Such a metastable β‐W phase results in an antiferromagnetic (AFM) order up to at least 500 K and highly conductive semiconducting behavior. The antiferromagnetism in the β‐W type V3Ga can be understood in terms of strong Coulomb repulsion and Hund's rule coupling between the nearest neighbor V 3d orbital states and their covalent bonding with the Ga 4p orbitals. These results are further verified by an exchange bias phenomenon revealed in antiferro/ferromagnet hybrid heterostructure of V3Ga and Fe films, where the strong hybridization between Fe 3d and V 3d orbital states at the interface gives rise to the robust perpendicular magnetic anisotropy therein. Herein, a novel route is used to prepare an AFM semiconductor material for antiferromagnet spintronics.