Search

The first principles calculations are carried out to understand the half metallic and ferromagnetic properties of Fe2−xCoxTiSi (x = 0, 0.5, 1, 1.5, 2) full Heusler alloys. The stable structure is predicted as L21 structure (Cu2MnAl phase). The lattice constant value of Fe2−xCoxTiSi Heusler compounds increases as the value of x increases. These alloys exhibit half metallic ferromagnetism (except Fe2TiSi) with small spin flip gap at the minority spin state. At high pressure, semiconductor to metallic phase transition is observed in Fe2TiSi while half metallic to metallic phase transition is observed in Fe1.5Co0.5TiSi, Fe1.0 Co1.0TiSi, Fe0.5Co1.5TiSi and Co2TiSi. The spin polarization of these compounds (except Fe2TiSi) is 100%. Hence, these compounds are suitable for spin injection devices in spintronics. [ABSTRACT FROM AUTHOR]

In this study, structural, electronic and magnetic properties of non-transition metal-based binary compounds X Bi (X = Ba, Sr and Ca) in five different phases: rock salt, NiAs, wurtzite, zinc blende and CsCl, are investigated in order to find new sp magnetic materials used for real spintronic and other related applications. The calculations are performed by a developed full-potential augmented plane wave plus local orbitals (FP-L/APW + lo) method within the spin density functional theory. As exchange-correlation potential, we used the generalized gradient approximation of Perdew, Burke, and Ernzerhof (GGA-PBE) and the modified Becke-Johnson potential mBJ-GGA-PBE form. It is found that the magnetic moment in these compounds is mainly contributed by the spin-polarized p orbitals of Bi atoms. The WZ XBi are true half-metallic ferromagnet with opposite spin direction at Fermi energy having a magnetic moment of 2.00 μ B per formula unit. [ABSTRACT FROM AUTHOR]

In this study, we have explored the structural, electronic, and magnetic properties of V-doped zincblende MgSe and MgTe compounds using density functional calculations. The Wu-Cohen generalized gradient approximation is used for optimizing the structural properties, while the modified Becke and Johnson local (spin) density approximation functional has been employed to compute the electronic and magnetic properties. The spin dependent band structures, electronic density of state, and magnetic moments calculated for V-doped MgSe and MgTe semiconductors exhibit occurrence of 100 % spin polarization at the Fermi level which confirms stable half-metallic ferromagnetism in these materials. The spin-down gaps and the half-metallic gaps are analyzed in terms of V- 3d and Se-4 p (Te-5 p) hybridization, where it is observed that the V- 3dstates play a key role in generating spin polarization and the magnetic moment in these compounds. The exchange constants N αand N β have been calculated to demonstrate the effects resulting from exchange splitting process. Furthermore, spin-polarized charge density calculation is presented for elucidating the bonding nature, while pressure dependence of total magnetic moment for three concentrations of V-doped MgSe and MgTe are also discussed. [ABSTRACT FROM AUTHOR]