Half-metallic Character Research Articles

Probing the structural, mechanical, electro-magnetic, thermodynamic and thermoelectric properties of inner-transition based RaXO3 (X: Pr and U) cubic perovskites via first principle calculations

Here, we present ab-initio calculations of the structural, mechanical, electronic, magnetic, thermodynamic and thermoelectric properties of two radium-based perovskites by using density functional theory. These compounds are cubic in nature. Computation of tolerance factor, structural optimization by using the equation of state assures the stability of the materials. Further, we have checked the mechanical stability of the materials by computing the different mechanical parameters. The observed data of B/G and Cauchy pressure for the present materials reveals the ductile nature. The spin polarized band structures and density of states illustrate the half-metallic nature of these materials with the band gap of (3.74 and 4.80) eV in spin down channel for RaPrO3 and RaUO3 alloys respectively. The total magnetic moments calculated via GGA and mBJ approximations were found to be integral in nature (1 and 2) μB, for RaPrO3 and RaUO3 alloys respectively which also is an indication of the half-metallic character of these materials. The effect of temperature and pressure on the different thermodynamic properties like the specific heat capacity, thermal expansion and Gruneisen parameter were studied using the quasi-harmonic Debye model. Finally, we have speculated the temperature dependent thermoelectric properties in terms of Seebeck coefficient, electrical conductivity, thermal conductivity and power factor. The summed -up properties suggest the applications of these materials in thermoelectrics, spintronics and thermoelectric generators outlooks.

First-principles calculations to investigate physical properties of oxide perovskites LaBO3 (B[dbnd]Mn, Fe) for thermo-spintronic devices

Oxide perovskite LaBO3 was extensively examined using first principles computations with density functional theory. Various exchange-correlation functionals were applied to investigate several of its physical properties. The compound's stability was validated through energy optimization in both ferromagnetic and non-magnetic phases, revealing that the ferromagnetic phase is more energetically stable. With the optimized lattice parameter, we explored various electronic, mechanical, magnetic, and thermodynamic properties. According to the GGA + U approximation, LaMnO3 and LaFeO3 exhibit half-metallic and semiconductor characteristics, respectively. The elastic constants, along with the elastic moduli (Y, B, and G) and Vickers hardness (Hv) number, were calculated to assess the mechanical properties of both compounds. Our simulation confirmed the ductile nature of the material by analyzing the Cauchy pressure, Poisson's ratio, and Pugh ratio. Additionally, thermodynamic parameters, including thermal expansion, specific heat capacity, and Debye temperature, were computed using the quasi-harmonic Debye model. The study's findings suggest that these materials are suitable for thermo-spintronic devices.

A DFT theoretical prediction of new half-metallic ferromagnetism, mechanical stability, optoelectronic and thermoelectric properties of ZnCrO3 perovskites for spintronic applications

ZnCrO3 perovskites structural stability, optoelectronic, mechanical, along with thermoelectric properties, have all been to be described by calculations based on density functional theory (DFT). To determine the exchange correlation potential, the well-known generalized gradient approximation (GGA) and integration of the mBJ potential were used. The perovskite shows that this is in a cubic structure with Fm3m symmetry. Additionally, to check the stability, cohesive energy, structural optimization, and mechanical stability were requirements. This perovskite was found to be brittle, and their mechanical stability enhanced by the elastic constants. The perovskite has a half-metallic character, as evidenced by the spin-polarized electronic band profile, the behavior of the dielectric constant, and absorption coefficient in the spin-up and down channels. In this article, we also looked at magnetism and the origin of the half-metallic gap. The unpaired electrons in the split d-orbitals of the M-sited elements in the crystal field are responsible for the half-metallic as well as magnetic characteristics. Excellent spin polarization at the Fermi level encourages perovskite's possible use in spintronic technologies. Lastly, we computed the thermoelectric parameters within a chemical potential at various temperatures (300 K, 600, 900 K) to explore the potential application in spin electronic devices. Our finding shows that the ZnCrO3 alloy is exceptionally promising for the next generation of spintronics and thermoelectric devices at room and high temperatures.

Porous CrO[formula omitted]: A ferromagnetic half-metallic member in sparse hollandite oxide family

A stable polymorph of CrO2 is predicted using PBE+U method. The porous material is isostructural with α−MnO2 making it the second transition metal oxide in sparse hollandite group of materials. However, unlike the anti-ferromagnetic semiconducting character of the α−MnO2, it is found to be a ferromagnetic half-metal. At Fermi level, the hole pocket has ample contribution from O−2p orbital, though, the electron pocket is mostly contributed by Cr−3dxy and Cr−3dx2−y2. A combination of negative charge transfer through orbital mixing and extended anti-bonding state near Fermi level is responsible for the half-metallic ferromagnetic character of the structure. A comparative study of rutile and hollandite CrO2 and hollandite MnO2 structures delineate the interplay between structural, electronic and magnetic properties. The material shows a robust magnetic character under hydrothermal pressure, as well as, the band topology is conserved under uniaxial strain. Moderate magneto-crystalline anisotropy is observed and it shows a correspondence with the anisotropy of elastic constants. Occurrence of type−II Weyl nodes and their evolution under pressure is explored.

Effect of Ti doping on phase stability and half-metallicity of the Co2FeGe compound: GGA and mBJ-GGA approaches

Density Functional Theory (DFT) calculations were performed using the full-potential linearized augmented plane wave (FP-LAPW) method to study the effect of Ti doping on Co2FeGe systems. The both GGA and mBJ-GGA formalisms were employed in this study. For both the L21 and XA structures, ferromagnetic, ferrimagnetic and paramagnetic phases were considered, and lattice optimization was conducted to determine the most stable magnetic phase. The Co2FeGe and Ti2FeGe Heusler alloys were found to be stable in the ferromagnetic state with the L21 structure. In contrast, the XA-type ordering was observed for the CoTiFeGe alloy. The density of states and band structure calculations for the CoTiFeGe (XA structure) alloy revealed half-metallic behavior, which is notable for its potential in achieving high spin polarization. Additionally, half-metallic character was observed for the Co2FeGe alloy with L21-type ordering when using the mBJ-GGA formalism. The calculated elastic constants confirmed that these systems satisfy the mechanical stability criteria. Furthermore, the systems with x = 0.00 (Co2FeGe) and x = 1.00 (Ti2FeGe) comply with the Slater-Pauling rule for half-metallicity in alloys, given by Mtot = NV-24. According to the mBJ-GGA method, the total magnetic moments of Co2FeGe and CoTiFeGe are 6 μB and 1 μB, respectively. Meanwhile, the Ti2FeGe compound follows the condition Mtot = NV-18 and has a total magnetic moment of approximately 2 μB. The optoelectronic properties were examined through analysis of the optical constants, confirming semiconducting behavior for both x = 0.00 and x = 1.00.

First-principles calculations and experimental studies on Cr2MnAl Heusler alloy nanoparticles for spintronics applications

In depth understanding of the magnetic, structural and electrical properties of Heusler alloys are crucial to achieve potential applications in spin-based device. Wherein, we report the synthesis of Cr2MnAl Heusler alloy nanoparticles (NPs) via co-precipitation method and also demonstrated their transport properties. Interestingly X-ray analysis confirms the cubic phase of the synthesized Heusler alloy NPs and transmission electron microscopy (TEM) analysis reveals that the Cr2MnAl as particle size of 10 ± 2 nm. Moreover, this particle size has adverse effect on symmetry of Cr2MnAl Heusler alloy due to their higher surface to volume ratio that significantly changes their magnetic and electrical properties. These NPs exhibit soft ferromagnetic properties with a Curie temperature (Tc) of 25 K. Besides, resistivity measurements indicate the semiconducting nature and also we report the observation of anomalous Hall effect. In addition, we support our experimental results by studying the electronic and magnetic properties of alloy using first principle calculations. This density functional theory reveals that Cr2MnAl has half metallic characteristics with high spin polarization. In light of above, this material can be used as intermediate layer to decouple the two ferromagnetic layers which acts as spin-polarized carriers in spin-based device.

Carbon Superstructure-Supported Half-Metallic V2O3 Nanospheres for High-Efficiency Photorechargeable Zinc Ion Batteries.

Photorechargeable zinc ion batteries (PZIBs), which can directly harvest and store solar energy, are promising technologies for the development of a renewable energy society. However, the incompatibility requirement between narrow band gap and wide coverage has raised severe challenges for high-efficiency dual-functional photocathodes. Herein, half-metallic vanadium (III) oxide (V2O3) was first reported as a dual-functional photocathode for PZIBs. Theoretical and experimental results revealed its unique photoelectrical and zinc ion storage properties for capturing and storing solar energy. To this end, a synergistic protective etching strategy was developed to construct carbon superstructure-supported V2O3 nanospheres (V2O3@CSs). The half-metallic characteristics of V2O3, combined with the three-dimensional superstructure assembled by ultrathin carbon nanosheets, established rapid charge transfer networks and robust framework for efficient and stable solar-energy storage. Consequently, the V2O3@CSs photocathode delivered record zinc ion storage properties, including a photo-assisted discharge capacities of 463 mA ⋅ h ⋅ g-1 at 2.0 A ⋅ g-1 and long-term cycling stability over 3000 cycles. Notably, the PZIBs assembled using V2O3@CSs photocathodes could be photorecharged without an external circuit, exhibiting a high photo conversion efficiency (0.354 %) and photorecharge voltage (1.0 V). This study offered a promising direction for the direct capture and storage of solar energy.

First-principles calculations of structural, magneto-electronic, mechanical, optical and thermoelectric properties of novel quaternary Heusler alloys type ZrCoYAs (Y= Fe and Mn)

To determine the structural, mechanical, electronic, magnetic, optical, and thermoelectric properties of novel quaternary Heusler alloys type ZrCoYAs (Y= Fe and Mn), we used DFT with WIEN2k. Our results showed that the ferromagnetic Y-type-III phase is more stable due to the higher negative values of their formation energy. We calculated and discussed the elastic constants Cij, which are used to calculate the mechanical properties. The Spin-polarized band structure and DOS calculations using the GGA-PBE and GGA + U approach display a metallic character. However, using the mBJ-GGA-PBE and mBJ-GGA + U approach show a half-metallic character, a semiconductor for the spin-down channel with a direct band gap of 0.61 eV with mBJ-GGA-PBE and 0.74 eV with mBJ-GGA + U for ZrCoMnAs and a direct band gap of 0.43 eV with mBJ-GGA-PBE and indirect band gap with 0.39 eV with mBJ-GGA + U for ZrCoFeAs, in contrast, the spin-up channel is metallic, with 100 % spin polarization and an integer magnetic moment of 1.00 μB for ZrCoMnAs and 2.00 μB for ZrCoFeAs, obeying the Slater-Pauling rule. The estimated Curie temperatures of ZrCoMnAs and ZrCoFeAs are 204 K using the new model, 421 K using MFA, and 385 K using the new model, 1627 K using MFA, respectively. As exchange-correlation potential, MBJ and MBJ + U provide a better description of the electronic and magnetic properties of ZrCoMnAs and ZrCoFeAs compounds. Important optical properties such as dielectric function, absorption coefficient, refractive index, optical conductivity, reflectivity, and electron energy loss function are calculated in the infrared, visible, and ultraviolet range. The static dielectric function suggests that ZrCoMnAs possesses greater polarizability. Both alloys exhibit similar behavior in the far ultraviolet region range and reach a maximum absorption in the ultraviolet range. The half-metallic character of both alloys is revealed from the reflectivity at zero frequency. The calculation of the thermoelectric properties shows positive Seebeck coefficients, indicating that these Heuslers are p-type. Furthermore, the highest power factor is observed at a temperature of 1400 K. The maximum value of ZT is ∼1.1 at 1400 K for ZrCoFeAs and ZrCoMnAs. These studies show that these alloys may have potential applications in the thermoelectric applications.

The half-metallicity, thermoelectric and optoelectronic attributes of K2CeB’X6 (B’=Ag, Cu & X=Cl, Br) for spintronics and renewable energies: A spin-polarized DFT study

The distinctive electronic characteristics of half-metallic materials make them exceptional as they pave the way for innovations in spintronics and other magnetic fields. We predict the ferromagnetism in half-metallic K2CeB’X6 (B’ = Ag, Cu & X = Cl, Br) perovskite halides by employing the spin-polarized computations. The tolerance factor, formation energies and optimization plots favor the structural stability of all perovskites. The K2CeB’X6 (B’ = Ag, Cu & X = Cl, Br) are half-metallic with a direct band gap of 2.59 eV, 2.53eV and 1.05eV, respectively, in the spin-down state, while the spin-up exhibit metallic character. The magnetic behavior is confirmed by the magnetic moment values. Several parameters for optical response are computed, showing the absorption in the visible and high energy spectrum. The spin-polarized response in terms of thermoelectric characteristics shows outstanding results. We have achieved the highest ZT values in spin-dn channel, which is unity for K2CeAgCl6, K2CeAgBr6 and 0.98 for K2CeCuCl6 at 300K. These values are continued even at higher temperatures with no significant change. The half-metallic characteristics with excellent thermoelectric attributes in the spin-dn channel provide the evidence to utilize these perovskites for spintronics and green technologies.

First-principles studies of the structural, mechanical, electronic, magnetic and transport properties of inner transition based RaMO3 perovskites (M = Cm, Bk)

In the quest for new materials, we introduce self-consistent ab initio simulations to investigate the structural and mechanical stability, electronic profile, and transport properties of f-electron-based RaMO3 (M = Cm, Bk) perovskites by employing density functional theory. The energy optimization indicates that these alloys exhibit stability in the ferromagnetic phase. The examination of mechanical parameters demonstrates the ductile nature of these materials. To elucidate the electronic structure of these alloys, we employed a combination of two approximations: Generalized Gradient Approximation (GGA) and GGA + mBJ. Both approximations confirm the alloys’ half-metallic character. The magnetic moments calculated using both approximations were approximately 6 µB for RaCmO3 and approximately 7 µB for RaBkO3. The thermoelectric performance of these materials is evaluated by investigating different transport parameters such as the Seebeck coefficient, electrical and thermal conductivity and power factor. The comprehensive investigation of these two alloys has the potential to expand their applications in spintronics, thermoelectric devices, and radioisotope thermoelectric generators (RTGs).

Enhancement of the magneto-electronic properties by GGA and TB-mBJ approaches for KMgO3 perovskite oxide

We investigate the structural, elastic, electronic and magnetic properties of KMgO3. First-principal calculations, based on the formalism of the density functional theory (DFT) and the method of full potential augmented and linearized plane waves (FP-LAPW) implemented in the Wien2k code. The exchange and correlation effects were treated by the following two approximations: generalized gradient approximation (GGA) and Tran-Blaha modified beck Johnson (TB-mBJ) potentials. After analyzing the obtained structural parameters, the results revealed that KMgO3compound is most stable in its ferromagnetic configuration. The formation energy value showed that this compound can be experimentally synthesized. Furthermore, the calculated band structures, and density of states (DOSs) indicate the half-metallic behavior of KMgO3. We found also that the total magnetic moment is an integer value of 3μBwhich confirms the half-metallic character. The magnetic moment specially issues from the spin-polarization of p electrons of O atoms.

Structural stability, electronic, magnetic, thermoelectric, optical and thermodynamic properties of CoTiFeGe and Co2Fe0.25Mn0.75-xTixGe alloys

Density Functional Theory (DFT) calculations are performed using full potential linearized augmented plane wave (FP-LAPW) method to study CoTiFeGe and Co2Fe0.25Mn0.75-xTixGe (x = 0, 0.25, 0.50, 0.75) systems through GGA and mBJ-GGA formalisms. The lattice equilibrium optimization was conducted to determine the stable magnetic phase state of these systems. It was found that the systems exhibit stability in a ferromagnetic nature, with the exception of the Co2Fe0.25Mn0.75Ge compound, which displays ferrimagnetic behavior. Electronic band structures and density of states for our systems show a half-metallic character using mBJ-GGA, except the Co2Fe0.25Mn0.75Ge system, which exhibits metallic behavior. Furthermore, the studied systems adhere to the Slater-Pauling rule condition for half-metallicity of alloys Mtot = ZV-24. Optoelectronic properties have been analyzed using optical parameters, confirming semiconducting behavior. Optical reflections with minimal loss and the existence absorption are observed in the infrared and visible areas suggest that the studied systems are suitable for optoelectronic devices. Additionally, a comprehensive assessment of the thermodynamic properties of the systems was carried out to investigate their thermodynamical stability against temperature and pressure change. The transport properties of these systems were systematically investigated, revealing that our alloys present the poor thermoelectric matter.

A comprehensive theoretical analysis on structural, electronic, optical, and mechanical properties of Sr2VRuO6 compound

In this paper, using the FP-LAPW technique as implemented in the Wien2k code, we have studied the structural, electronic, optical, and mechanical properties of strontium-based compound Sr2VRuO6. In this study, we explore the properties of Sr2VRuO6 using various approximations. We present the total energy versus energy, employing the Wu-Cohen-Generalized Gradients Approximation (WC-GGA) for both nonmagnetic and ferromagnetic states. To determine the stability of this material in cubic structure, the tolerance factor (t) and octahedral factor (μ) have been calculated. The lattice parameters of Sr2VRuO6 were determined, and subsequent calculations yielded the compressive modulus, Young's modulus, shear modulus, and Poisson's ratio in both two and three dimensions. Analyzing the band structure of Sr2VRuO6 within the mBJ-GGA approximation the half metallic character is observed with an indirect bandgap of 2.34 eV. In addition, the total and partial density of states, as well as charge density maps for Sr2VRuO6 have been calculated. Furthermore, we investigated the real and imaginary parts of the dielectric function as functions of energy for Sr2VRuO6. Additionally, the study delved into the variation of the refractive index, absorption coefficient, reflectivity, and energy loss with respect to energy for Sr2VRuO6.

Comprehensive investigation of half Heusler alloy: Unveiling structural, electronic, magnetic, mechanical, thermodynamic, and transport properties

This study employs density functional theory (DFT) using Wien2k to comprehensively analyze the essential properties of two half-Heusler alloys, KCrSi and KCrGe. Our findings demonstrate that the ferromagnetic Type 2 configuration exhibits superior stability over non-magnetic and antiferromagnetic states for all KCrZ (Z = Si, Ge) alloys. These alloys exhibit complete spin polarization and half-metallic character, with calculated magnetic moments of 3 μB for both KCrSi and KCrGe. The Curie temperature (TC) is determined using the mean field approximation. Mechanical stability is assessed through second-order elastic constants (SOECs), and electronic properties are analyzed using local spin density approximation (LSDA), Perdew-Burke Generalized Gradient Approximation (PBE-GGA), and Tran-Blaha modified Becke-Johnson (TB-mBJ) schemes, confirming the retention of the half-metallic nature. The negative enthalpy of formation (ΔH) suggests material stability. The use of semi-classical Boltzmann theory, incorporated through the sophisticated scheme of BoltzTraP, explores transport coefficients. High pressures and temperature discrepancies in thermodynamics are considered by implementing the quasi-harmonic Debye approximation to illustrate stability. Finally, optical properties are summarized to assess the applicability of this alloy for optoelectronic applications. The overall characteristics of these particular alloys suggest potential applications in sustainable thermoelectric and optoelectronic features.

Investigating the dilute magnetic semiconductor behavior of 4d transition metal adsorption on B4C3

We conducted a systematic investigation of B4C3 adsorbed with 4d-transition metals (4d-TMs), including Tc, Cd, Mo, Nb, Rh, Ru, and Ag, using first principles. This study involved an evaluation of structural, electronic, and magnetic properties. When single atom adsorption was adsorbed to B4C3 using elements such as Tc, Nb, Rh, Ru, and Ag, it demonstrated characteristics of a diluted magnetic semiconductor (DMS), manifesting magnetic moments. Conversely, Cd, Mo, and Pd exhibited behavior consistent with non-magnetic semiconductors. Ferromagnetic (FM) and antiferromagnetic (AFM) arrangements were formed through the adsorption of 2TM atoms on B4C3. In the FM setup, Ru and Nb uphold their roles as DMS. Interestingly, Tc and Rh exhibit half-metal behavior in this configuration, displaying their potential utility in spintronics applications. In the AFM configuration, Tc displayed half-metallic behavior, while the other metals maintained the same characteristics observed in the case of single TM adsorption. The reactivity of Nb-B4C3 is notably high owing to its low work function, whereas Cd-B4C3 is observed to be less reactive. AFM coupling is favorable in the 2Nb-, 2Rh-, and 2Ru-B4C3 systems, while 2Tc-B4C3 displays FM coupling. Transition metals belonging to the 4d series hold the potential to enhance the properties of B4C3, including its half-metallic, metallic, and semiconductor characteristics. These findings suggest the potential use of 4D transition metals adsorbed on B4C3 as a prospective material for spintronics and magnetic storage applications in the future.

Intrinsic room-temperature ferromagnetism in two-dimensional ternary transition metal tellurides CrX2Te4 (X = Al, Ga, and In)

A tremendous amount of research has witnessed the exploration of two-dimensional (2D) materials with intrinsic ferromagnetism and diverse physical properties. However, the low Curie temperature and deficient magnetic anisotropy hinder their practical applications in nanoscale spintronics. Based on first-principles calculations, we propose a new family of 2D ternary transition metal tellurides, CrX2Te4 (X = Al, Ga, and In), with both structural and magnetic stabilities at room temperature. Our calculations demonstrate that the 2D CrX2Te4 crystal exhibits the intrinsic 100% spin-polarized half-metallic feature with spin-up metallic and spin-down semi-conducting properties. With the remarkable magnetic moment of 4 μB per Cr atom, both 2D CrAl2Te4 and CrGa2Te4 crystals perform robust ferromagnetism with the out-of-plane magnetic anisotropy, while the 2D CrIn2Te4 crystal prefers the in-plane easy magnetization axis. The Monte Carlo simulation based on the 2D Heisenberg model shows that the critical Curie temperatures of the 2D CrAl2Te4, CrGa2Te4, and CrIn2Te4 crystals could reach 466, 431, and 536 K, respectively. Moreover, the magnetic exchange strength and magnetic anisotropy could be further enhanced by the in-plane biaxial strain. The novel electronic and magnetic features promote 2D CrX2Te4 (X = Al, Ga, and In) crystals as a new family of two-dimensional intrinsic ferromagnetic materials for next-generation advanced spintronics.

Exploring half-metallicity and pressure-induced effect in inverse heusler alloys: First principle DFT investigations of Cr2XZ (X = Ni, Pd, Pt; Z = Al, Ga, Si, Ge)

In this study, we have predicted a set of inverse Heusler alloys (HA) based on transition metals, specifically Cr2XZ (X = Ni, Pd, and Pt; Z = Al, Ga, Si, and Ge), using density functional theory (DFT) calculations. The structural, electronic, magnetic, and elastic properties, of Cr2XZ HAs have been investigated in detail to evaluate their potential for spintronic applications. Our electronic structure analysis involved the examination of band structure (BS) and density of states (DOS) to elucidate the half-metallic and magnetic characteristics of the alloys. The results indicate that Cr2XZ alloys stabilize in the F 4‾ 3 m space group in the Hg2CuTi type inverse structure, displaying a ferrimagnetic (FiM) ground state. Notably, among the inverse HAs, Cr2NiAl, and Cr2PtSi exhibit intriguing half-metallic properties with 100% spin polarization at the Fermi level (EF). Furthermore, under the influence of pressure, there is evidence of a nearly half-metallic nature in Cr2PtAl and Cr2PdGe, while the nearly half-metallic traits persist up to compressive pressures of 55 GPa and 40 GPa for Cr2PtAl, and Cr2PdGe, respectively. The Born stability criteria confirm the mechanical stability of the Cr2XZ HAs, with Cr2NiZ (Z = Al, and Ga), Cr2PdZ (Z = Ga, and Ge), and Cr2PtAl exhibiting a brittle nature, and Cr2NiZ (Z = Si, and Ge), Cr2PdZ (Z = Al, and Si), and Cr2PtZ (Z = Ga, Si, and Ge) exhibiting ductility.

Dioxides transition metal monolayers: A first-principles calculations

We carried out first-principles computational calculations within the framework of density functional theory using the generalized gradient approximation along with the pseudo-potential method, in order to investigate the structural and electronic properties and the energy stability of ternary bidimensional alloys based on TMxV1-xO2 (TM = Cr, Mo, and W) for x = 0.0, 0.25, 0.50, 0.75, and 1.0 transition metal dioxides in the 1H structure (group #187). We found that the values of the lattice constants of the VO2, CrO2, MoO2 and WO2 monolayers are in good agreement with reported results and that the lattice constants of ternary alloys obey Vegard's law, with a maximum deviation of 0.362% (less than 1%) for the alloy W0.25V0.75O2. We found that the values calculated for formation energies are negatives, therefore the ternary monolayers are thermodynamically stable. In addition, we found that the Cr0.25V0.75O2 monolayer has a half-metallic character with a magnetic moment of 1.0 μB/cell, while the Mo0.25V0.75O2 and W0.25V0.75O2 monolayers exhibit a metallic behavior, with magnetic moments of 0.40 μB/cell and 1.16 μB/cell, respectively. These magnetic properties come from the hybridization between the V-d, Cr-d, and O-p orbitals. The TMxV1-xO2 (TM = Cr, Mo, and W, with x = 0.50 and 0.75) alloys exhibit a metallic behavior and do not exhibit magnetic properties. In particular, we carried out a study of the mechanical and dynamic stability of the Cr0.25V0.75O2 monolayer, in view of the fact that it is the system of greatest interest for applications in spintronics, through calculations of the elastic constants (a criterion for mechanical stability) and calculations of the vibrational properties of the lattice (phonons).

Critical behavior, structural, electronic, and magnetic properties of the Heusler alloy: CoFeCrP

In this work, we study the equiatomic quaternary Heusler alloy (EQHA) CoFeCrP using two methods: density functional theory (DFT) and Monte Carlo simulations. The DFT method allowed us to illustrate the structural, electronic, and magnetic properties of this alloy. The ground state phase diagrams have been presented to show the stable configurations in different physical parameter planes. On the other hand, the Monte Carlo simulations, performed under the Metropolis algorithm, permitted to deduce the critical the behavior of the EQHA CoFeCrP. The structural properties results show that the phase of type I, of this alloy is the most stable configuration. In addition, the band structures and density of states calculations results show that this compound exhibits a half-metallic character with a 100% of spin polarization (SP) at the Fermi-level. The total magnetic moment of the Heusler compound is found to be 4.00 µB. Moreover, it is found that the Slater-Pauling is well described for this alloy. Our results show that this material is a potential candidate for the spintronic applications. This is due to its half-metallicity, its high spin moments, its complete SP polarization, and its high Curie temperature.

First principle studies on half-metallicity and pressure-induced half-metallic band gap in 3-d transition metal-based quaternary Heusler ScVCoZ (Z = Si, Ge, Sn, P, As, and Sb) alloys

In the present work, we predict a series of 3-d transition metals-based quaternary Heusler alloys (QHA) ScVCoZ (Z = Si, Ge, Sn, P, As, and Sb) (SVCZ), by employing density functional theory (DFT) calculations. We carried out extensive band structure (BS) and density of states (DOS) analysis to explain the half-metallic and magnetic behavior of the alloys. We found that SVCZ alloys stabilize in the F 4̅ 3m space group and exhibit a ferromagnetic (FM) ground state (GS). Among the QHAs, SVCZ (Z = Si, Ge, and Sb) exhibit intriguing half-metallic properties featuring 100% spin polarization at the Fermi level (EF). Additionally, the effect of pressure indicates a band gap opening in one of the spin channels for SCVZ (Z = P, and As), and the half-metallic characteristics are retained up to a compressive pressure, respectively of 65, and 79 GPa for SCVP and SCVAs. Elastic properties calculations suggest SVCZ alloys satisfy Born stability criteria and are mechanically stable. Among the predicted QHAs, SVCZ (Z = Si, Ge, and Sn) shows brittle nature, whereas SVCZ (Z = P, As, and Sb) are ductile.