Search

The first-principle calculations of density functional theory were used to study the structural, electronic, magnetic, mechanic, and half-metallic behavior of Y2MnZ (Z = Al, Ga, In) within the spin generalized gradient approximation. These compounds can be experimentally synthesized due to their negative values of the calculated formation energies. Our calculations indicate that they are more stable in Cu2MnAl-type structure. The Hg2CuTi-type structure displays half-metallic characteristic with 100% spin polarization at the Fermi level. The value of calculated magnetic moment has an integer value of 2μB for Y2MnZ (Z = Al, Ga, In) in the Hg2CuTi-type structure which well matches with magnetic moments predicted from Slater–Pauling rule. Therefore, the Y2MnZ (Z = Al, Ga, In) in the Hg2CuTi-type structure is predicted to be a candidate for possible spintronics applications. [ABSTRACT FROM AUTHOR]

The structural, electronic and magnetic properties of half-Heusler compounds XVSb (X = Fe, Co and Ni) are investigated by using the density functional theory with generalized gradient approximation (GGA), and Tran-Blaha modified Becke-Johnson (TB-mBJ) exchange potential approximation. It is found that the half-metallic gaps are generally reasonably widened by mBJ as compared to the GGAapproximation. The magnetic proprieties of XVSb (X = Fe, Co and Ni) are well defined within mBJ with an exact integer value of magnetic moment. The band gaps given by TB-mBJ are in good agreement with the available theoretical data. The FeVSb exhibits a semiconductor nature. The CoVSb and NiVSb present half-metallic behaviour with total magnetic moment of and 2B in good agreement with Slater-Pauling rule. These alloys seem to be a potential candidate of spintronic devices. [ABSTRACT FROM AUTHOR]

The structural, electronic, and magnetic properties of the half-Heusler MTiSb (M = Fe, Co, Ni) compounds have been examined using the first-principles calculations with the full-potential linear augmented plane wave (FP-LAPW) method within the density functional theory. The electronic structures and magnetic properties of MTiSb (M = Fe, Co, Ni) are studied. It is found that the calculated lattice parameter is in good agreement with the theoretical values. Using the general gradient approximation (GGA), we observe that for the three compounds, the α phase is more stable than β and γ phases. CoTiSb is a semiconductor, NiTiSb is a metal, while the FeTiSb compound is a half-metallic, and the total magnetic moments are 0.00085, − 0.26074, and 0.99353 μ B, respectively, which is in agreement with the Slater-Pauling rule, Furthermore, the origin for the appearance of the half-metallic band gap in the FeTiSb compound was also discussed. [ABSTRACT FROM AUTHOR]

First-principles density functional theory (DFT) calculations with the generalized gradient approximation (GGA) have been performed to investigate electronic band structures and magnetic and half-metallic characteristic of TiCoAlSn ( x = 0, 0.25, 0.50, 0.75, 1). The optimized equilibrium lattice constants were found to be equal to 6.08 and 6.37 Å for TiCoAl and TiCoSn, respectively. These ternary Heusler compounds are found to be a complete half-metal with a total magnetic moment of 2 and 3 μ , respectively, which is in good compliance with the Slater-Pauling rule, M = Z − 18. The spin-polarized band structures and density of states (DOS) of the TiCoAlSn (0.25, 0.50, and 0.75) Heusler alloys confirm that they are half-metal due to the presence of the energy gap in the minority spin. Consequently, TiCoAlSn ( x = 0, 0.25, 0.50, 0.75, 1) alloys are predicted to be a promising candidate for the practical applications in spintronic devices. [ABSTRACT FROM AUTHOR]

The structural, electronic, and magnetic properties of the full-Heusler compounds CoMnZ ( Z = Al, Ge, Si, Ga) have been investigated using the first-principles calculations with the full-potential linear-augmented plane wave method within the density functional theory. The electronic structures and magnetic properties of the CoMnZ ( Z = Al, Ge, Si, Ga) compounds with both HgCuTi- and CuMnAl-type structures are studied. It is found that the calculated lattice constants are in good agreement with the theoretical values. Using the general gradient approximation, we observe that the CuMnAl-type structure is more stable than the HgCuTi type. The CoMnZ ( Z = Al, Ge, Si, Ga) compounds were half-metallic ferromagnets in the CuMnAl-type structure. The total magnetic moments of the CoMnZ ( Z = Al, Ge, Si, Ga) compounds in the CuMnAl-type structure were 4, 5, 5, and 4 μ respectively, which is in agreement with the Slater-Pauling rule, m = N−24 Furthermore, the origin for the appearance of the half-metallic band gap in the CoMnZ compound was also discussed which shows them to be promising materials for possible spintronics applications. [ABSTRACT FROM AUTHOR]

The structural, electronic as well as the magnetic properties of the Co2CrX (XAl, Ga and In) full-Heusler alloy have been studied using first-principles calculations performed in the framework of density functional theory (DFT) within the generalized gradient approximation (GGA). It was taken into account both possible L21 structures (i.e. Hg2CuTi- and Cu2MnAl-type). Basically, for all compounds, the Cu2MnAl-type structure is energetically more stable than Hg2CuTi-type structure at the equilibrium volume. The electronic structure calculations for Co2CrAl reveal that half-metallic (HM) character in Cu2MnAl-type structure, Co2CrGa show nearly HM behavior and Co2CrIn has a metallic character. The predicted total magnetic moment is for Co2CrX (XAl, Ga) which is in good convergence with the Slater-Pauling (SP) rule. [ABSTRACT FROM AUTHOR]

In this paper, ab initio electronic structure calculations are applied to study half-metallic properties of Heusler alloys XMnGe (X = Sc, Fe, Ni) with both CuHgTi-type and AlCuMn-type structures using first-principles calculations based on density functional theory (DFT). The exchange-correlation energy of electrons is described in the generalized gradient approximation (GGA). The results showed that for all compounds XMnGe, the AlCuMn-type structure is energetically more stable than CuHgTi-type structure at the equilibrium volume. The ScMnGe and FeMnGe are half-metallic in the CuHgTi- and AlCuMn-type structures, respectively; finally, NiMnGe have a metallic character in both CuHgTi- and AlCuMn-type structures. [ABSTRACT FROM AUTHOR]

We investigate the structural, electronic and magnetic properties of the full Heusler compounds Mn2YSn (Y=Mo, Nb, Zr) by first-principles density functional theory using the generalized gradient approximation. It is found that the calculated lattice constants are in good agreement with the theoretical values. We observe that the Cu2MnAl-type structure is more stable than the Hg2CuTi type. The calculated total magnetic moments of Mn2NbSn and Mn2ZrSn are 1/n; and 2/n; at the equilibrium lattice constant of 6.18 and 6.31, respectively, for the Cu2MnAl-type structure. Mn2MoSn have a metallic character in both Hg2CuTi and Cu2MnAl type structures. Thetotal spin magneticmoment obeys the Slater-Pauling rule. Half-metal exhibits 100% spin polarization at the Fermi level. Thus, these alloys are promising magnetic candidates in spintronic devices. [ABSTRACT FROM AUTHOR]

The structural, half-metallic, and elastic characteristics of XZrAs (X = Cr, Mn, and V) half-Heusler compounds were theoretically calculated using the WIEN2k code. For the term of the potential exchange and correlation (XC), we calculated structural, electronic, and magnetic properties using the generalized gradient approximation (GGA). The type 1 arrangement in ferromagnetic (FM) phases is more energetically stable than other type arrangements in all compounds. The spin-up electrons of both XZrAs (X = Cr, Mn) half-Heusler compounds in the type III structure are semiconducting with energy gaps, whereas the spin-dn electrons are metallic. Research has also been done on the VZrAs compound, which exhibits metallic characteristics in both type I and type III structures. XZrAs (X = Cr, Mn, and V) half-Heusler compounds are elastically stable and ductile, according to calculated Cij elastic constants. Finally, at equilibrium lattice constants a = 6.1196 A° for MnZrAs and 6.142 A° for CrZrAs, real half-metal ferromagnetic materials (HMF) were produced from XZrAs (X = Cr, Mn) half-Heusler compounds within 3 µB and 2µB, respectively. [ABSTRACT FROM AUTHOR]

In this paper, we use the 1rst-principles calculations based on the density functional theory to investigate structural, electronic and magnetic properties of Fe2YSn with (Y = Mn, Ti and V). The generalized gradient approximation (GGA) method is used for calculations. The Cu2MnAl type structure is energetically more stable than the Hg2CuTi type structure. The negative formation energy is shown as the evidence of thermodynamic stability of the alloy. The calculated total spin moment is found as 3µB and 0µB at the equilibrium lattice constant for Fe2MnSn and Fe2TiSn respectively, which agrees with the Slater-Pauling rule of Mt = Zt -24. The study of electronic and magnetic properties proves that Fe2MnSn and Fe2TiSn full-Heusler alloys are complete half-metallic ferromagnetic materials. [ABSTRACT FROM AUTHOR]

First-principle calculations were performed in the frame work of the density functional theory (DFT) using FP-LAPW method as implemented in Wien2k code to determine the structural stability, electronic and magnetic properties of Rh2CrGe1-xAlx (x = 0, 0.25, 0.50, 0.75 and 1). The results showed that for Rh2CrAl and Rh2CrGe, the Cu2MnAl-type structure is energetically more stable than Hg2CuTi-type structure at the equilibrium volume. The calculated densities of stats for Rh2CrAl and Rh2CrGe show half metallic and nearly half metallic behavior respectively. Rh2CrGe1-xAlx (x = 0.25, 0.50, 0.75) these alloys show half metallic character, and these compounds are predicted to be good candidates for spintronic applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • Based on DFT calculations, the XFeGe (X = Co, Cr, Ni) half Heusler alloys were investigated. • Half metallic behavior is explained via spin polarization results. • Magnetic and electronic properties for the XFeGe (X = Co, Cr, Ni) were studied. • The calculated elastic constants for the three compounds verified the mechanical stability criteria for cubic systems. The structural, electronic, magnetic and thermodynamic properties of XFeGe (X = Co, Cr, Ni) half Heusler compounds are studied using first-principles calculation within density functional theory in five different atomic configurations. For each configuration, their optimized lattice constants are determined. It showed that the configuration of type 3 is energetically the most stable. From the spin-polarized band structure and density of states, it is found that CoFeGe alloy exhibits a half-metallic character with integer magnetic moments of 3.00μ B per formula unit at their equilibrium volume, whereas NiFeGe and CrFeGe exhibit a metallic character. These results indicate that the magnetic moment mainly originates from the Fe atoms. The calculated equilibrium volume for the three compounds CoFeGe, CrFeGe, and NiFeGe at various temperatures is predicted. The heat capacity at constant volumeC V has been calculated as a function of temperature and pressure. Additionally, the calculated elastic constants for the three compounds confirm the mechanical stability criteria for cubic systems. [ABSTRACT FROM AUTHOR]