Half-metallicity feature within Ag-doped zincblende WGe alloys: DFT+U insights

Abstract

By employing the full-potential linearized augmented plane wave (FP-L/APW[Formula: see text]lo) technique based on density functional theory (DFT), the structural, electronic and magnetic properties of zincblende W[Formula: see text]AgxGe alloys ([Formula: see text] and 0.25) are scrutinized thoroughly. Based on the generalized gradient approximation (GGA), the exchange-correlation energy functional is included in the current simulation. For computing the structural features, the GGA approximation is applied, whereas GGA, [Formula: see text] and the modified Burke–Johnson of [Formula: see text] (TB-mBJ-[Formula: see text] approximations are incorporated to perform the calculations of electronic and magnetic behaviors of these alloys. The structural analysis of the alloys indicated that the total energy of the W[Formula: see text]Ag[Formula: see text]Ge alloy was favorable in the ferromagnetic ground state. The spin-polarized electronic structure shows the half-metallic behavior of the W[Formula: see text]Ag[Formula: see text]Ge alloy, while the WGe compound is identified as a metal. The magnetic results obtained from the half-metallic W[Formula: see text]Ag[Formula: see text]Ge alloy increasingly support the full half-metallicity of this compound because an integer value is acquired for the total magnetic moment. The strong hybridization between 4p-Ge and 3d-W states brings forth weak local magnetic moments at the nonmagnetic Ge atomic sites and reduces the local magnetic moment of the W atomic sites from its free space charge.