Half-metallic ferromagnetism in Be1−x V x Te alloys: an Ab-initio study

Abstract

First-principles calculations of the structural, elastic, electronic, magnetic and thermodynamic properties of zinc blende Be 1-x V x Te alloys (x = 0, 0.25, 0.50, 0.75 and 1) based on spin-polarized density functional theory are performed using full-potential augmented plane wave method, within the spin generalized gradient approximation for the exchange-correlation potential. The equilibrium structural parameters such as lattice constant (a 0 ), bulk modulus (B 0 ) and first pressure derivative of bulk modulus (B 0 ) are optimized for all alloys. The elastic constants C 11 , C 12 , C 44 and anisotropy coefficients are also estimated. The calculations of the band structure and the density of states demonstrate that all Be 1-x V x Te (x = 0.25, 0.50, 0.75 and 1) alloys are complete half-metals. The investigation of the band structure and the density of states demonstrate that Be 0.75 V 0.25 Te alloy is entirely half-metal, whereas Be 0.50 V 0.50 Te and Be 0.25 V 0.75 Te alloys are nearly half-metal. The estimation of the s(p)-d exchange splitting constants N 0a (conduction band) and N 0b (valence band), as obtained through the density of states, have been used to indicate the magnetic behavior of the compounds. From the total magnetic moment, it is observed that the p-d hybridization reduces the local magnetic moment of V atom from its free space charge of 3l B and generates small local magnetic moments on the nonmagnetic Be and Te sites. Lastly, based on the quasi-harmonic Debye model, the obtained macroscopic thermodynamic properties, such as thermal expansion coefficient, heat capacities and Debye temperate, are presented in detail.

First-principles investigation on the magnetism of low-concentration 3d (Cr, Mn, Fe Co, Ni)-doped BeTe semiconductors

“…Alay-e-Abbas et al [14] have systematically investigated ZB Be 1Àx Cr x Te (x ¼ 0.25, 0.5, 0.75, 1) compounds and found that they are all ferromagnetic HMs. The half-metallicity of the V-doped BeTe semiconductors has also been predicted by Doumi et al [15], Sajjad et al [16] and Monir et al [17]. Since the doping concentration of transition metals in semiconductors is limited and very low in experiments, the lowconcentration doping must also be considered.…”

Exploring the Mn doped BaTe alloy for spintronics and energy harvesting applications

“…Bouhafs et al explored the optoelectronic, elastic, geometric, and vibrational characteristics of BaSe 1−x Te x by FP-LAPW method in which the ternary alloys have wide direct E g semiconductors and increasing concentration provide increase redshift of optical spectra [37]. Additionally, Monir et al reported the physical characteristics of V-doped BeTe and observed that the lattice constant increase with the rise in concentration and V-atom particularly participate to total μ B [38]. Recently, various computational work has been done to examine the magnetic and half metallic FM features of SCs such as Mn/V-doped BaS [39,40], Mn-doped BeTe [20], V/Cr-doped BeTe [41], Ni-doped CdSe [42] and Cr-doped BaTe [43].…”