First-Principles Calculations of the Phonon, Mechanical and Thermoelectric Properties of Half-Heusler Alloy VIrSi Alloys

Adebambo, Paul O.; Adetunji, B.I.; Uto, Oghenekevwe T.; Kenmoe, Stéphane; Adebayo, G.A.

doi:10.3390/cryst12121838

Cited by 6 publications

(2 citation statements)

References 37 publications

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“…Full-potential linearized augmented planewave method (FLAPW) was employed in Ref [32] for band structure that utilizes LAPW basis functions and the full Coulomb potential to account for all electrons (both core and valence) thereby accurately describing the electronic states near to the atomic cores and the interstitial regions between atomic sites [57]. Upon analyzing the band structure, it was observed that the conduction band minimum (CBM) of NbIrSn is situated at the X point of the Brillouin zone (BZ), while the valence band maximum (VBM) is located at the W point of the Brillouin zone (BZ) similar to that reported in VIrSi [31].…”

Section: Electronic and Magnetic Propertiesmentioning

confidence: 76%

A first-principles assessment of the thermoelectric properties in half-heusler compound NbIrSn

Khatri,

Adhikari

2023

Phys. Scr.

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Converting waste heat into electric power using thermoelectric materials could significantly address global energy needs. Half-Heusler compounds exhibit significant promise as thermoelectric materials suitable for high temperatures, thereby offering a potential solution to address the energy crisis. By employing density functional theory (DFT), semi-classical Boltzmann transport theory (BTE), and density functional perturbation theory (DFPT), this study thoroughly examines the structural, electronic, magnetic, phonon, mechanical, and thermoelectric properties of 18 valence electron half Heusler compound NbIrSn. Considering the presence of heavy 5d transition element Ir in our compound, all calculations are carried out with and without spin–orbit coupling (SOC). This material display both dynamic and mechanical stability, and also possess the property of ductility as indicated by Pugh's ratio and Poisson's ratio. NbIrSn is identified as non-magnetic semiconductors with indirect band gaps of 0.65 eV and it reduces to 0.63 eV when SOC is included. The different transport parameters are analyzed in relation to the chemical potential and doping concentrations for different temperatures. The lattice thermal conductivity of the material at room temperature is measured to be 13.40 Wm-1K-1 and 14.81 Wm-1K-1without and with SOC respectively. The optimal zT values for NbIrSn at 1200 K are 0.98 with p-type doping and 0.31 with n-type doping. Incorporating SOC leads to a substantial improvement, raising the optimal zT values to 1.33 for p-type doping and 0.47 for n-type doping. In conclusion, incorporating SOC is essential when analyzing the characteristics of the proposed compound. The present study highlights NbIrSn as a potentially a favorable candidate for p-type doping on high-temperature power generation.

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Section: Electronic and Magnetic Propertiesmentioning

confidence: 76%

A first-principles assessment of the thermoelectric properties in half-heusler compound NbIrSn

Khatri,

Adhikari

2023

Phys. Scr.

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“…In the present work, our primary focus is on calculating κ l of hH XNiSn (X=Ti, Zr, Hf) using Slack's equation. We obtained the required parameters for the equation from two different approaches: from elastic constants by QHA in thermo_pw code [29] implemented in Quantum ESPRESSO and the slopes of acoustical branches of phonon bands using DFPT [30].…”

Section: Introductionmentioning

confidence: 99%

Lattice thermal conductivity in half-Heusler compounds XNiSn (X=Ti, Zr, Hf) using Slack's model

Khatri,

Adhikari

2024

BIBECHANA

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Reducing lattice thermal conductivity (κl) that reflects the material’s heat-carrying capacity through lattice phonon vibrations is crucial for optimizing the figure of merit (zT). Using density functional theory (DFT) and density functional perturbation theory (DFPT), present work considers the structural, electronic, magnetic, and phonon properties of the XNiSn (X=Ti, Zr, Hf ) half Heusler (hH) compounds. TiNiSn, ZrNiSn, and HfNiSn are identified as semiconductors with indirect band gaps of 0.43 eV, 0.47 eV and 0.39 eV, respectively, exhibiting dynamical stability. The temperature- dependent κl of hH XNiSn are compared using Slack’s model with two approaches for analyzing phonon velocity: elastic constants from quasi- harmonic approximation (QHA) as implemented in the Thermo_pw code and slope of phonon bands based on DFPT. At room temperature, TiNiSn, ZrNiSn and HfNiSn have κl values of 28.61 Wm−1K−1, 34.61 Wm−1K−1 and 29.85 Wm−1K−1 respectively using phonon velocity from slopes of phonon bands based on DFPT. These values show deviation of 1.48%, 6.29%, and 5.82% to those κl values 29.01 Wm−1K−1’, 36.79 Wm−1K−1 and 31.59 Wm−1K−1 for TiNiSn, ZrNiSn and HfNiSn respectively using QHA.

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Ab initio predictions of thermoelectric, mechanical, and phonon characteristics of FeTiSe half-Heusler compound

Nenuwe,

Agbawe

2023

Current Applied Physics

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First-Principles Calculations of the Phonon, Mechanical and Thermoelectric Properties of Half-Heusler Alloy VIrSi Alloys

Cited by 6 publications

References 37 publications

A first-principles assessment of the thermoelectric properties in half-heusler compound NbIrSn

A first-principles assessment of the thermoelectric properties in half-heusler compound NbIrSn

Lattice thermal conductivity in half-Heusler compounds XNiSn (X=Ti, Zr, Hf) using Slack's model

Ab initio predictions of thermoelectric, mechanical, and phonon characteristics of FeTiSe half-Heusler compound

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