Doping isolated one-dimensional antiferromagnetic semiconductor vanadium tetrasulfide (VS4) nanowires with carriers induces half-metallicity

Abstract

Quasi one-dimensional (1D) vanadium tetrasulfide (VS₄) nanowires (NWs) are synthetic semiconductors which combine with each other through van der Waals interactions to form bulk phases. However, the properties of these individual NWs remain unknown. Nevertheless, our calculations of their stability indicate that VS₄ NWs can be separated from their bulk structures. Accordingly, we theoretically investigated the geometrical, electronic, and magnetic properties of bulk phase and isolated VS₄ NWs. Our results indicate that both bulk phase and isolated VS₄ NWs are semiconductors with band gaps of 2.24 and 2.65 eV, respectively, and that they prefer the antiferromagnetic (AFM) ground state based on DFT calculations. These calculations also suggested that isolated VS₄ NWs show half-metallic antiferromagnetism upon electron and hole doping because carrier doping splits the spin degeneracy to induce local spin polarisation. As a result, spin polarisation currents in isolated VS₄ NWs can be manipulated with locally applied gate voltage. Therefore, these 1D AFM materials have a high potential for advancing both fundamental research and spintronic applications because they are more resistant to magnetic perturbation than their 1D ferromagnetic counterparts.