Semiconducting and magnetic properties within B(1-x)VxAs alloys at x = 0 and x = 0.25: A DFT + U study

Abstract

The physical (mechanical (structural and elastic), electronic and magnetic) properties of the zincblende BAs parent compound and its B0.75V0.25As alloy are analyzed by employing the FP-L/APW + lo method as implemented in WIEN2k code, where the XC potential is approached by the GGA approximation. The analysis of the structural properties in B0.75V0.25As system indicates its stability in ferromagnetic state, where its computed equilibrium lattice parameters (the lattice constant (a0), the bulk modulus (B0), and the first-pressure derivative (B’) of the bulk modulus) are given. The elastic moduli (C11, C12, and C44) and anisotropy factor for the cubic system are determined for these compounds in the purpose to confirm their mechanical stability. The electronic structure of B0.75V0.25As shows its complete semiconducting feature. The electronic density of states indicates that the uncompleted 3d-V orbitals broaden on the width of the exchange splitting energies (Δx(d) and Δx(pd)); accordingly, the effective potential of minority-spin electrons are more attracted comparing to the majority-spin electrons. The magnetic properties unveil that the value of total magnetic moment of B0.75V0.25As alloy is found in an integer number. Thus, the hybridization between 3d-V and 4p-As states pushes to reduce the atomic magnetic moment of V element from its free space charge value and to produce local magnetic moments on B and As nonmagnetic sites. Moreover, the s-d exchange constant of conduction band (N0α) and the p-d exchange constant of valence band (N0β) are evaluated in the reason to know contributions during the exchange splitting process.

Keywords

• B0.75V0.25As alloy
• Elastic moduli
• Semiconducting feature
• Electronic and magnetic properties
• FP-L/APW+lo
• DFT+U calculations