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We have looked at a very interesting class of Heusler alloy that has received a lot of theoretical research but a very little experimental attention. Mn2TiSi Heusler alloy was synthesized by a conventional vacuum arc remelting process. The formation of Heusler phase along with the secondary phases was observed after annealing it at 773 K for 120 h. The X-ray diffraction pattern illustrates the presence of cubic B2 disordered phase along with a secondary phase with a lattice parameter of 5.82 Å. The microstructure and compositional analysis of Mn2TiSi alloy shows the presence of distribution of Mn, Ti, and Si elements according to their stoichiometric ratio. The magnetic measurements show a ferromagnetic nature with Curie temperature (TC) around 203 K. With low magnetic moment and coercivity, Mn2TiSi can be used for switching applications because of its fast magnetization reversal. So, Mn2TiSi becomes the greatest choice for use in spintronics due to its low magnetic moment and low coercivity. [ABSTRACT FROM AUTHOR]

We predict a series of XYZ-type half-Heusler RuMnZ (Z = Si, Ge, Sn, P, As, Sb, Se, and Te) alloys, using density functional theory (DFT) calculations. Structural, electronic structure, magnetic moments, and elastic properties are carried out using both GGA and GGA+U approximations to determine the viability of this series of alloys for spintronic applications. The band structure (BS) and density of states (DOS) calculations are carried out to explain the half-metallic and magnetic nature of the predicted alloys. RuMnZ alloys stabilize to the F 4 ¯ 3 m space group with a ferrimagnetic (FiM) ground state, with the exception of RuMnSn, which has a ferromagnetic (FM) ground state. Interestingly, RuMnP/As/Te alloys exhibit half-metallic properties with 100% spin polarization at the Fermi level among the predicted alloys. When U is included in the calculations (GGA+U), the half-metallicity is completely lifted. Further, upon incorporating pressure under GGA+U, a band gap is induced again, and the half-metallicity in RuMnTe is robust up to a compressive pressure of 140 GPa. Calculation of the elastic properties shows that RuMnZ has a ductile nature. [ABSTRACT FROM AUTHOR]

Here, we report the experimental investigations on magnetic (spin polarization and exchange bias) and transport (spin-flip and spin-flop) properties of Co2FeSi Heusler compound at cryo temperature and high magnetic field. The spin cluster characteristic of the material is revealed by the M[T] curve of the ZFC, FC, and FW cycles. This can exhibit spin polarization behavior of anti-ferromagnetism (AFM) at 30–70 K. Furthermore, at a critical field of 0.2 T, AFM transforms into ferromagnetic (FM) and on further increasing the magnetic field, the spin polarization region becomes linear due to perseverance of FM behavior. The isothermal magnetization [M(H)] are also evaluated at different temperatures and AFM to FM transition has been observed at various applied magnetic fields. These magnetic measurements are used to determine exchange bias [EB] parameters such as HE, HC, and Mr both at low and room temperature. The resistivity [ρ(T)] has been measured at 0 and 5 T field, which explain the increasing trend of metallic nature at cooling cycle and also provides a clear evidence of magnonic, phononic resistivity and spin-flip scattering. [ABSTRACT FROM AUTHOR]

The first principle calculation to investigate the structural, optoelectronic, and magnetic properties of the Y2FeSi Heusler alloy (HA) using the Wien2K code has been discussed in detail in the present manuscript. To estimate the physical properties of the HA, PBE-GGA and mBJ exchange–correlation functional were applied. The electronic charge density contour plot represents the dominant ionic character among the atomic configurations of Y2FeSi compound. Density of states (DOS) across the Fermi level (EF) exhibits the prominent role of Fe-3d electronic states along with Y-4d and Si-2p electronic states. Estimated spin polarization (SP ~ 75%) from the DOS profile suggests the metallic nature with magnetic (ferromagnetic having magnetic moment ~ 1.65 µB/cell for the HA) ordering of the compound. Phonon spectra represents the dynamical stability of the Y2FeSi compound. Additionally, the consequence of spin–orbit coupling (SOC) on material's physical properties was also explored. Band structure (BS) with SOC effect shows additional energy levels across the EF, due to splitting of Y-atoms' energy levels. A dielectric function was assessed with and without SOC to study the optical properties. Overall, Y2FeSi HA reveals interesting electronic, magnetic, and optical properties that have the potential for application in optical and spintronic devices. [ABSTRACT FROM AUTHOR]

We have carried out ab initio density functional theory (DFT) calculations on the DO3-type Cr3Z (Z = P, As, Sb, S, Se, and Te) alloys with the aim of predicting new half-metallic (HM) magnetic materials for potential spintronics applications. From the structural and magnetic calculations, we find that Cr3Z (Z = As, Sb, S, Se, and Te) alloys stabilized to ferrimagnetic (FiM) state, while Cr3P alloy stabilized in non-magnetic state. The spin-polarized density of states (DOS) calculation reveals that, among all the alloys, only the Cr3Sb exhibits HM-FiM nature at the equilibrium lattice constant with total integer magnetic moment of − 1 μB, satisfying the Slater-Pauling (S-P) rule and thus offering 100% spin polarization at the Fermi level. Further, both Cr3As and Cr3Te alloys show nearly half-metallic (NHM) behavior, while Cr3P, Cr3S, and Cr3Se alloys behave as usual metallic materials. Interestingly, in all the Cr3Z (Z = P, As, Sb, S, Se, and Te) alloys, the total magnetic moment is mainly contributed by Cr(Y) atoms. We also attempt to rationalize the origin for the observed HM band gap in terms of molecular orbital (MO) hybridization mechanism. Finally, the influence of sp atoms on the structural, electronic, magnetic, and half-metallic properties of Cr3Z (Z = P, As, Sb, S, S, and Te) alloys is studied systematically. [ABSTRACT FROM AUTHOR]

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]

In this paper, an ab initio study of the electronic and magnetic properties of CdS doped by the transition metal elements has been investigated. Based on the KKR-CPA method within the Generalized Gradient Approximation (GGA), we have calculated the total energy to determine the most stable state in the system and found it to be the ferromagnetic state for Ti, V and Cr-doped CdS, while it is the stabilization in spin glass states for Mn and Co cases. On the other hand, we have investigated and plotted the density of states (DOSs) which reveals that the doped compounds exhibit a half-metallic character. The spin polarization at Fermi level is estimated and found to be around 100%. Furthermore, we have identified the type of mechanism of exchange interactions being double exchange for all components except Mn case where we find that the responsible mechanism is the p-d exchange. The evaluation of the Curie temperature variation TC for the three components stable in the ferromagnetic phase revealed values greater than 300 K for most cases. The effect of the crystal field and the exchange splitting as a function of the concentrations values has been also investigated. Half-metallic substances are very interesting for spin-dependent electronics devices as they boost their magnetoresistance capacity. [ABSTRACT FROM AUTHOR]

High-spin-polarized materials are the promising candidates in spintronic devices. Here, the spin-polarized electronic structure, magnetism, and mechanical properties of Ti2.25Co0.75Si and Ti2.25Co0.75Si0.5X0.5 (X = As and Sb) Heusler alloys were calculated by first-principles calculations. The results show that Ti2.25Co0.75Si and Ti2.25Co0.75Si0.5Sb0.5 are ferromagnetic half-metals with 100% spin polarization, while Ti2.25Co0.75Si0.5As0.5 is a zero-gap half-metal. The complete spin-polarized characteristics of Ti2.25Co0.75Si and Ti2.25Co0.75Si0.5X0.5 are confirmed to be robust to hydrostatic and uniaxial strains. The results of the elastic constants and phonon spectra demonstrate the mechanical and dynamic stabilities of Ti2.25Co0.75Si and Ti2.25Co0.75Si0.5X0.5 alloys. Furthermore, the magnetic anisotropy results show that the easy magnetic axis of Ti2.25Co0.75Si can be tuned from the in-plane direction to the out-of-plane one under the uniaxial strains. Ti2.25Co0.75Si and Ti2.25Co0.75Si0.5X0.5 (X = As and Sb) alloys are promising candidates for the potential application in spintronic devices. [ABSTRACT FROM AUTHOR]

In this manuscript, we study the structural, electronic, and magnetic properties of the equiatomic quaternary Heusler alloy ZnCdRhMn in the framework of the first-principle calculations and Monte Carlo simulations. In fact, we have investigated the structural, the magnetic, and the electronic properties of the Zn-based equiatomic quaternary Heusler alloy ZnCdRhMn using the ab initio method in the bases on the GGA approximation. On the other hand, the critical behavior of the equiatomic quaternary Heusler alloy ZnCdRhMn has been outlined by the Monte Carlo simulations. For this end, we apply the Metropolis algorithm. The objective of this work is to improve the competition between the austenitic and martensitic phases on the existence of magnetic and electronic properties of this alloy. The half-metallic behavior is only improved for the austenitic structure and 100% of spin polarization has been found. Moreover, a high curie temperature is found for this alloy for the austenitic phase. We can conclude that the austenitic structure of this alloy is useful for the spintronic device applications. [ABSTRACT FROM AUTHOR]

In recent years, Heusler alloys have attracted extensive attention because of their usefulness in spintronic devices. In this paper, the structural, electronic, and magnetic properties of full Heusler alloys Rh2ZrX (X = Al, Ga, In, Si, Ge, Sn) have been studied using Quantum Espresso software package based on density functional theory. Calculations have been done by GGA and GGA+U methods. The investigations on the structural properties of the alloys showed that the Rh2ZrSi alloy had the most stable structure (Ecoh = − 1.807 eV) among the six compounds reviewed. The results of GGA calculation on electronic properties of Rh2ZrX alloys show that while the Rh2ZrX (X = Al, Ga, In) alloys had metallic nature due to overlapping between conduction and valance band at Fermi level for both spin directions, the Rh2ZrX (X = Si, Ge, Sn) alloys had half-metal characteristic. Also, Rh2ZrSi and Rh2ZrGe alloys had 100% spin polarization. By studying the magnetic properties, it was found that the Rh2ZrAl and Rh2ZrSi alloys were antiferromagnetic, while the Rh2ZrGa, Rh2ZrIn, Rh2ZrGe, and Rh2ZrSn alloys were ferromagnetic materials. Also, the total spin magnetic moment of alloys was found in accordance with the Slater-Pauling rule. The results obtained using GGA+U calculation are slightly different from the results of GGA calculation. [ABSTRACT FROM AUTHOR]

The structural, electronic, magnetic, and optical properties of Mn-based Heusler Mn2ZrGa1−xGex (x = 0, 0.25, 0.5, 0.75, and 1) alloys are calculated by first-principles full-potential linearized augmented plane wave plus local orbital (FP-LAPW+lo) method. It is found that Mn2ZrGa1−xGex alloys are half-metallic ferrimagnetic and their magnetic moments are in good agreement with the Slater-Pauling relationship. The calculations reveal that all alloys have a pseudo-gap in the majority-spin channel except for x = 0.75 and x = 1 which have a real gap in the majority-spin channel. The spin polarization is quite large for whole series, and it reaches to a value of 100% for x = 0.75 and x = 1. Our calculated results clearly show that with the Ge substitution, the lattice parameter linearly decreases while the bulk modulus increases. Moreover, the calculated formation energies confirm that these alloys are stable chemically. The optical properties, including the real and imaginary parts of the dielectric function, reflectivity, and absorption spectra, were also investigated. The results show that the dominant behavior, at energy below 1 eV, is due to interactions of free electrons in the system. The increment of Ge concentration leads to an increase in the plasma frequency of metallic spin channel. [ABSTRACT FROM AUTHOR]

First-principles calculations within full-potential linear-augmented plane-wave method using the generalized gradient approximation were carried out for the electronic and magnetic properties of the CoCrGaSi Heusler alloys. The electronic structure calculations show a conservation of the minority spin gap supporting the half-metallic character of the CoCrGaSi alloys. The substitution of Ga by Si results in linear increasing of total magnetic moment as silicon concentration increases following the Slater-Pauling rule that is in agreement with experimental data. [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]

A first-principles study on the electronic structure and magnetic properties of the RuZrSb Heusler compound has been performed by using the self-consistent full-potential linearized augmented plane wave (FPLAPW) method. It is found that the AlCuMn-type structure exhibits half-metallic ferrimagnetism and is preferable energywise than the CuHgTi-type structure. The total spin magnetic moment is based on mainly the Ru atoms and obeys the Slater-Pauling rule. The calculated total magnetic moment of RuZrSb is −1.0 μ at the equilibrium lattice constant 6.497 Å for the AlCuMn-type structure. The spin-down electrons are metallic, but the spin-up bands are semiconductor with a gap of 0.388 eV, and the spin-flip gap is 0.313 eV. The AlCuMn-type RuZrSb Heusler compound keeps a 100 % of spin polarization for lattice constants ranging between 6.40 and 6.53 Å. The Curie temperature is estimated to be 322.7 K in the mean field approximation (MFA). [ABSTRACT FROM AUTHOR]

The structural and electronic properties of Heusler alloys CoCrZ (Z=In, Sn, Sb) have been studied using the generalized gradient approximation (GGA) and local spin density approximation (LSDA), respectively. Among the systems under investigation, CoCrSb gives 100 % spin polarization at E. CoCrSb is the most stable Half-Metallic Ferromagnets (HMFs) with an energy gap 0.25 eV at the Fermi level in the spin-down channel. We have also found that the increase in the total magnetic moment as Z goes from In to Sb. The calculated density of states (DOS) and band structures shows the half-metallic ferromagnets (HMF) character of CoCrSb. [ABSTRACT FROM AUTHOR]

The electronic and magnetic properties of the CrYSb (Y=Co, Fe, and Ni) Heusler alloys with both CuHgTi-type and AlCuMn-type structures have been investigated using first-principles calculations based on density functional theory (DFT). Two nearly half-metallic ferrimagnets (HMFs), CrCoSb, and CrFeSb in CuHgTi-type structure, are predicted. The energy gap lies in the minority spin band for both alloys. The calculated total spin magnetic moments are 2 μ and 1 μ per unit cell for CrCoSb and CrFeSb alloys, respectively, which are in good agreement with the Slater-Pauling relation. For these alloys, the magnetic moments of Y and Cr(B) are antiparallel to that of Cr(A) and all of these moments increase with increasing lattice constant. It was also found that the half-metallic properties of CrCoSb and CrFeSb are unaffected to the lattice distortion and the half-metallicity can be obtained within the wide range of 5.52-6.07 Å and 5.96-6.16 Å for CrCoSb and CrFeSb alloys, respectively. [ABSTRACT FROM AUTHOR]