Density functional study of half-metallic property on B2 disordered Co2FeSi

Abstract

First principle calculations on the magnetic properties and spin polarization of the B2 disordered Co 2 FeSi full Heusler alloy have been carried out along with that of ordered L2 1 structure. The linear augmented plane wave method, within the LDA?U approximation, gives the magnetic moment value as predicted by Slater-Pauling rule. A small band gap in the minority band structure around the vicinity of the Fermi level results in half-metallicity or 100 % spin polarization in L2 1 ordered structure. The calculations also showed that the half-metallicity vanishes at moderate percentages of B2 disorders due to creation of new states around the Fermi level in the minority DOS but at low and high levels of disorder, the half-metallicity was retained. The variation in the magnetic moments of Co 2 FeSi with change in the % disorder was attributed to the changes in the local magnetic moments of Co, Fe, and Si atoms which vary with change in % disorder.

Monocrystalline Heusler Co2FeSi alloy glass-coated microwires: Fabrication and magneto-structural characterization

“…However, recent theoretical investigation on the spin polarization of fully ordered L2 1 and fully disordered B2 structure of Co 2 FeSi Heusler alloy reveals that both systems are half metallic. [2] Lately studies [13,[23][24][25][26] have shown that the half-metallic character and structural disorder of Heusler alloys can be predicted by simple electrical resistivity variation with temperature. In our case, the resistivity data was found to fit well with the relations presented in the published work by Bombor et al, [26].…”

“…The production of spintronic devices has intensified the search for new materials, especially halfmetals, exhibiting room temperature ferromagnetism [1,2]. This extraordinary behaviour can be understood via distinct character of energy bands for spin up and spin down states.…”

Effect of Fe substitution on the electronic structure, magnetic and thermoelectric properties of Co 2 FeSi full Heusler alloy: A first principle study

“…2 the total DOS of Co 2Àx Fe 1+x Si are shown in the left side and respective partial density of states are given in the right side. It has been already reported that the pure Co 2 FeSi in L2 1 structure shows a small indirect band gap in the minority DOS confirming the half-metallicity [19]. Hence, the DOS of Co 2 FeSi is not shown in Fig.…”

“…The electronic structure of Co 2 FeSi with three different types of disorders (Co-Fe, Co-Si and Fe-Si) has been studied by Li et al [18] and it was showed that Fe-Si type disorder is most likely to occur. Theoretical investigation on the B2 type disorder in Co 2 FeSi depicts that the half metallicity can be retained even at its higher level [19]. The half metallic behavior of Co 2Àx Fe 1+x Si alloys with varying x has not been investigated theoretically so far.…”

Гальваномагнитные свойства сплавов Гейслера Co-=SUB=-2-=/SUB=-FeZ (Z=Al, Si, Ga, Ge, In, Sn, Sb)

“…Поэтому для них спра-ведлива " классическая" теория Стонера [7]. В настоящее время рассматриваемые сплавы интенсивно исследуются как экспериментальными методами [8][9][10][11], так и теоре-тически [10,[12][13][14]. Наибольшее количество научных ра-бот посвящено выяснению особенностей их магнитных и электрических свойств, а также " первопринципным" расчетам электронной зонной структуры.…”