Investigation of high pressure and temperature study of thermo-physical properties in semiconducting Fe2ZrSi Heusler

Int J of Quantum Chemistry

2020

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Self-consistent ab-initio calculations with highly precise spin-polarized, density functional theory have been performed for the first time, to investigate the electronic structure, magnetism, transport, elasto-mechanical, and thermophysical properties of newly tailored Mn-based full-Heuslers. The cohesive and ground-state energy calculations in ferromagnetic, nonmagnetic, and antiferromagnetic states confirm the stability of materials in face-centered ferromagnetic configuration. The spin-based band structure analysis is well defined by modified Becke-Johnson potential with the occurrence of half-metallic character along the Fermi level. Estimation of elastic parameters is used to check the mechanical stability and nature of forces occurring in materials, where we see the alloys display ductile nature along with a Debye temperature of 398.75 K for Mn 2 NbAl, 337.53 K for Mn 2 NbGa, and 360.52 K for Mn 2 NbIn. Furthermore, within the solution of Boltzmann theory, thermoelectric efficient parameters address its applications in energy harvesting and solid-state device applications. Thermodynamic potentials have been keenly predicted by implementing quasi harmonic Debye model to descript its stability at high temperature and pressure varying conditions. The prediction of ground state and thermodynamic properties from extensive first-principles calculations could be beneficial for its future experimental insights with intriguing applications. Hence, the overall theme from the current study creates an application stand in spintronics, power generation, as well as green energy sources for future technologies. K E Y W O R D S delocalized d electrons, elastic properties, half-metallicity, lattice thermal conductivity, power factor, Seebeck coefficient | INTRODUCTIONNoteworthy consideration on the intermetallic Heusler alloys has attracted attentions over decades as they demonstrate amazing capabilities like robust spin-polarization, magneto-resistance, gapless semiconductor based on spin to gigantic magneto-caloric, phase transition half-metallic magnetism, and thermoelectric (TE) effects. [1][2][3][4][5][6][7] Spintronics is a swiftly advanced area in the field of modern technology. Those types of ultramodern high machinery electronics based on spin system are used to transport modernizes in high-technological fields. [8,9] The TE and spintronics are the off-shoots of halfmetallic ferromagnetism (HMF) used in semiconductors possessing ferromagnetic (FM) character, [10] magnetic tunnel junctions, [11] typically uses the data in semantic memory Scheme [12] and some material that exhibits both FM and semiconductor properties offers the exciting outlook of combining nonvolatile magnetic storage, and conventional semiconductor electronics. [13] TE materials [14,15] are the alternate sources of energy for regulating the

“…It is regarded a dynamic quantity by which all thermodynamic parameters as well as chemical bonding can be elucidated. Per atom cohesive energy for a crystal can be obtained as:…”

Section: Resultsmentioning

confidence: 99%

Investigation of structural, elastic, thermophysical, magneto‐electronic, and transport properties of newly tailored Mn‐based Heuslers: A density functional theory study

Int J of Quantum Chemistry

2020

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“…Macroscopic distortion of a crystal structure is directly related to the elastic constants and is applicable in the evaluation of elastic energies or strains in materials under applied (internal/external/thermal) stresses. 29 These constants are determined by the linear response of a crystal towards the external forces, and are also associated with structural stability, equation of state (EOS) interatomic potential and phonon spectra. Consequently, the determination of elastic constants is necessary to characterize a solid crystal.…”

Section: Resultsmentioning

confidence: 99%

Current research and future prospective of cobalt‐based Heusler alloys as thermoelectric materials: A density functional approach

2020

Int J Energy Res

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Energy harvesting along with the thermoelectric materials has been investigated over recent decades with increased interest. This is not only due to their structural capability for demonstrating and integrating various new concepts to enhance the thermoelectric figure of merit but also high thermal stability, which is useful for thermoelectric devices. In the present investigation, we have used density functional theory combined with Boltzmann transport scheme to predict the properties of Co 2 XAl (X = Zr, Nb, Hf) Heuslers. The elastic parameters are simulated to determine the strength and ductile nature of these materials. Three different methods for exchange correlations are utilized to investigate the band profile for that modified Becke-Johnson potential illustrates the better results than generalized gradient approximation and GGA + U functional. The band profile found to be n-type (indirect band-gap) for Co 2 NbAl and p-type (direct band-gap) for Co 2 ZrAl and Co 2 HfAl Heuslers near the Fermi level. The formation and cohesive energy approve the thermodynamic stability of these materials. The band occupation and density of states in the post DFT treatment are used to predict the relations among various transport properties. The most important lattice portion of thermal conductivity has been keenly determined by Slack's equation. The half-metallic nature along with efficient thermoelectric parameters, including electrical conductivity, Seebeck coefficient, thermal conductivity, power factor, and zT suggest the likelihood of these materials to have a potential application in designing the shape of memory devices and imminent thermoelectric and energy harvesting materials.

“…In order to determine them, we have used the rhombohedral and tetrahedral distortions on the cubic structure under volume conserving constrain. The requirement on these elastic constants leads to the following restrictions C 11 > 0, C 12 > 0, C 44 > 0, ( C 11 − C 12 ) > 0, and C 12 < B < C 11 defined by Born–Haung [59–62]. The detailed discussion of different parameters has been precisely written is shown in Table 4.…”

Section: Resultsmentioning

confidence: 99%

“…The requirement on these elastic constants leads to the following restrictions C 11 > 0, C 12 > 0, C 44 > 0, (C 11 − C 12 ) > 0, and C 12 < B < C 11 defined by Born-Haung [59][60][61][62]. The detailed discussion of different parameters has been precisely written is shown in Table 4.…”

Section: Mechanical Stabilitymentioning

confidence: 99%

Robustness in ferromagnetic phase stability, half‐metallic behavior and transport properties of cobalt‐based full‐Heuslers compounds: A first principles approach

Int J of Quantum Chemistry

2020

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Heusler alloys fill up the demanding gaps and becomes a point of prestige due to their interesting multi‐dimensional and remarkable applications in future technologies like spintronics and thermoelectrics. Self‐consistent ab‐initio calculations with highly precise spin‐polarized density functional theory associated with Boltzmann transport scheme have been perform to investigate the structural stability, mechanical, magneto‐electronic, thermo‐physical and thermoelectric transport properties of Co2VX (X = Sn, Sb) Heuslers. The equilibrium lattice parameters at the cost of structural optimizations are observed to agree with the available experimental data. The occurrence of perfect band occupation and interpretation of density of states through the modified version of Becke Johnson scheme delivers more precise and accurate results rather than GGA and GGA + U, possessing an indirect band gap of 1.12 eV and 1.34 eV in spin down channel of Co2VX (X = Sn, Sb) Heuslers respectively. Robustness of various elastic constants and its other associated mechanical constituents against external forces is checked to define the stability of these alloys. The transport parameters like Seebeck coefficient, electrical and thermal conductivity, power factor and zT have been put together to express their thermoelectric response. Conservative estimates of Seebeck coefficient and zT demonstrate its extending application stand in thermoelectric energy harvesting technologies. Furthermore complete and precise description of thermo‐physical behavior of the vital quantities like Debye temperature, thermal expansion, Grüneisen parameter and specific heat were examined to check its thermo‐dynamical stability against temperature and pressure variation.