Electronic, phonon and thermoelectric properties of RbLaGe half-Heusler alloy: A DFT study including spin-orbit coupling
DOI:
https://doi.org/10.31349/RevMexFis.72.020502Abstract
The phonon, electronic and structural properties of the novel RbLaGe half-Heusler alloy are analysed using density functional theory (DFT) with the generalized gradient approximation (GGA). The semiclassical Boltzmann transport theory under the constant relaxation time approximation is employed specifically to evaluate the thermoelectric properties. The results reveal that RbLaGe is energetically, structurally, and dynamically stable, suggesting its potential for experimental synthesis. RbLaGe exhibits semiconducting behaviour with a direct bandgap, 0.79 eV. Spin-orbit coupling has a more pronounced effect on the conduction band other than on the valence band, leading to a splitting of 0.01 eV approximately at point X. Thermoelectric properties, including power factor (P F/τ ), merit figure (ZT), electronic thermal conductivity (κe/τ), electrical conductivity (σ/τ ) and Seebeck coefficient, are analyzed using Boltzmann transport theory within the rigid band approximation. The results propose that RbLaGe exhibits high thermopower, which is attributed to the flat band near the Fermi level. Furthermore, the power factor (P F) shows a strong temperature dependence, reaching a maximum value,9.9 × 10¹¹ W/mK²s at 900 K. The calculated thermal conductivity of the lattice (κL) reveals a significant temperature-dependent reduction, improving the merit thermoelectric figure (ZT). Incorporating spin-orbit coupling (SOC) further improves ZT by optimizing the electronic transport properties.
References
S. Cheng, et al., High sensitivity five band tunable metamaterial absorption device based on block like Dirac semimetals, Optics Communications 569 (2024) 130816, https://doi.org/10.1016/j.optcom.2024.130816
Z. Chen et al., Ultra wideband absorption absorber based on Dirac semimetallic and graphene metamaterials, Physics Letters A 517 (2024) 129675, https://doi.org/10.1016/j.physleta.2024.129675
S. Chen and Z. Ren, Recent progress of half-Heusler for moderate temperature thermoelectric applications, Materials today 16 (2013) 387, https://doi.org/10.1016/j.mattod.2013.09.015
F. Casper et al., Half-Heusler compounds: novel materials for energy and spintronic applications, Semiconductor Science and Technology 27 (2012) 063001, https://doi.org/10.1088/0268-1242/27/6/063001
D. Kieven et al., I-II-V half-Heusler compounds for optoelectronics: Ab initio calculations, Physical Review B-Condensed Matter and Materials Physics 81 (2010) 075208, https://doi.org/10.1103/PhysRevB.81.075208
J. Yang et al., Evaluation of half-Heusler compounds as thermoelectric materials based on the calculated electrical transport properties, Advanced Functional Materials 18 (2008) 2880, https://doi.org/10.1002/adfm.200701369
J. Zhou et al., Large thermoelectric power factor from crystal symmetry-protected non-bonding orbital in half-Heuslers, Nature communications 9 (2018) 1721, https://doi.org/10.1038/s41467-018-03866-w
H. Missoum et al., High ZT of new half-Heusler LiXZ (X= La, Y and Z= Ge, Si) alloys at room temperature, Journal of Physics and Chemistry of Solids 193 (2024) 112186, https://doi.org/10.1016/j.jpcs.2024.112186
N. A. Ganie, S. A. Mir, and D. C. Gupta, Tantalum halfHeusler alloys RbTaSi and RbTaGe: potential candidates for desirable thermoelectric and spintronic applications, RSC advances 13 (2023) 7087, https://doi.org/10.1039/D3RA00146F
C. J. Palmstro m, Heusler compounds and spintronics, Progress in Crystal Growth and Characterization of Materials 62 (2016) 371, https://doi.org/10.1016/j.pcrysgrow.2016.04.020
A. Lorf et al., Structural and Half-Metallic Stabilities of the Half-Heusler Alloys KNaAs, KRbAs and NaRbAs: First Principles Method, In Spin, vol. 11 (World Scientific, 2021) p. 2150010, https://doi.org/10.1142/S2010324721500107
N. Marbouh et al., Theoretical Prediction of Structural Stability, Electronic, Elastic, and Magnetic Properties of the New Half Metallic Half-Heusler XSrC (X= Li and Na) Alloys, In Spin, vol. 12 (World Scientific, 2022) p. 2250027, https://doi.org/10.1142/S2010324722500278
J. Wei, Y. Guo, and G. Wang, Exploring structural, mechanical, and thermoelectric properties of half-Heusler compounds RhBiX (X= Ti, Zr, Hf): A first-principles investigation, RSC advances 13 (2023) 11513, https://doi.org/10.1039/D3RA01262J
R. J. Quinn and J.-W. G. Bos, Advances in half-Heusler alloys for thermoelectric power generation, Materials advances 2 (2021) 6246, https://doi.org/10.1039/D1MA00707F
H. Zhuet al., Half-Heusler alloys as emerging high power density thermoelectric cooling materials, Nature communications 14 (2023) 3300, https://doi.org/10.1038/s41467-023-38446-0
A. Honget al., Full-scale computation for all the thermoelectric property parameters of half-Heusler compounds, Scientific reports 6 (2016) 22778, https://doi.org/10.1038/srep22778
K. K. Johariet al., High thermoelectric performance in ntype degenerate ZrNiSn-based half-heusler alloys driven by enhanced weighted mobility and lattice anharmonicity, ACS Applied Energy Materials 4 (2021) 3393, https://pubs.acs.org/doi/10.1021/acsaem.0c03152
G. Rogl, M. J. Zehetbauer, and P. F. Rogl, The effect of severe plastic deformation on thermoelectric performance of skutterudites, half-Heuslers and Bi-tellurides, Materials Transactions 60 (2019) 2071, https://pubs.acs.org/doi/10.2320/matertrans.MF201941
G. Roglet al., Half-Heusler alloys: Enhancement of ZT after severe plastic deformation (ultra-low thermal conductivity), Acta Materialia 183 (2020) 285, https://doi.org/10.1016/j.actamat.2019.11.010
W. Xieet al., Recent advances in nanostructured thermoelectric half-Heusler compounds, Nanomaterials 2 (2012) 379, https://doi.org/10.3390/nano2040379
T. Zhuet al., High efficiency half-Heusler thermoelectric materials for energy harvesting, Advanced Energy Materials 5 (2015) 1500588, https://doi.org/10.1002/aenm.201500588
A. Shuklaet al., Electronic structure and thermoelectric properties of CoTiSi half-Heusler alloy: Doping overtones, AIP Advances 15 (2025), https://doi.org/10.1063/5.0242686
S. Matth, S. Pandey, and H. Pandey, Unravelling the effect of strain on the electronic structure, elastic and thermoelectric properties of half-Heusler alloy CoHfSi, Physica Scripta 100 (2024) 015928, https://doi.org/10.1088/1402-4896/ad96f2
B. Sahniet al., Reliable prediction of new quantum materials for topological and renewable-energy applications: A highthroughput screening, The Journal of Physical Chemistry Letters 11 (2020) 6364, https://doi.org/10.1021/acs.jpclett.0c01271
Y. O. Ciftci and S. D. Mahanti, Electronic structure and thermoelectric properties of half-Heusler compounds with eight electron valence count-KScX (X= C and Ge), Journal of Applied Physics 119 (2016), https://doi.org/10.1063/1.4945435
Y. Cherchab and R. Gonzalez-Hernandez, Structural stability and thermoelectric properties of new discovered half-Heusler KLaX (X= C, Si, Ge, and Sn) compounds, Computational and Theoretical Chemistry 1200 (2021) 113231, https://doi.org/10.1016/j.comptc.2021.113231
D. Hoat and M. Naseri, Electronic and thermoelectric properties of RbYSn half-Heusler compound with 8 valence electrons: spin-orbit coupling effect, Chemical Physics 528 (2020) 110510, https://doi.org/10.1016/j.chemphys.2019.110510
W. Kohn and L. J. Sham, Self-consistent equations including exchange and correlation effects, Physical review 140 (1965) A1133, https://doi.org/10.1103/PhysRev.140.A11330
J. P. Perdew, K. Burke, and M. Ernzerhof, Generalized gradient approximation made simple, Physical review letters 77 (1996) 3865, https://doi.org/10.1103/PhysRevLett.77.3865
F. Tran, P. Blaha, and K. Schwarz, Band gap calculations with Becke-Johnson exchange potential, Journal of Physics: Condensed Matter 19 (2007) 196208, https://doi.org/10.1088/0953-8984/19/19/196208
F. Tran and P. Blaha, Accurate band gaps of semiconductors and insulators¡? format?¿ with a semilocal exchangecorrelation potential, Physical review letters 102 (2009) 226401, https://doi.org/10.1103/PhysRevLett.102.226401
D. Koller, F. Tran, and P. Blaha, Improving the modified BeckeJohnson exchange potential, Physical Review B-Condensed Matter and Materials Physics 85 (2012) 155109, https://doi.org/10.1103/PhysRevB.85.155109
M. Bouhbou et al., Magnetic, half-metallicity and electronic studies of Cd1-xZnxCr2Se4 chromium selenospinels, Journal of Magnetism and Magnetic Materials 476 (2019) 86, https://doi.org/10.1016/j.jmmm.2018.12.063
K. Schwarz and P. Blaha, Solid state calculations using WIEN2k, Computational Materials Science 28 (2003) 259, https://doi.org/10.1016/S0927-0256(03)00112-5
P. B. Allen and M. Liu, Joule heating in Boltzmann theory of metals, Physical Review B 102 (2020) 165134, https://doi.org/10.1103/PhysRevB.102.165134
G. K. Madsen and D. J. Singh, BoltzTraP. A code for calculating band-structure dependent quantities, Computer Physics Communications 175 (2006) 67, https://doi.org/10.1016/j.cpc.2006.03.007
A. Togo and I. Tanaka, First principles phonon calculations in materials science, Scripta Materialia 108 (2015) 1, https://doi.org/10.1016/j.scriptamat.2015.07.021
D. Koelling and B. Harmon, A technique for relativistic spin-polarised calculations, Journal of Physics C: Solid State Physics 10 (1977) 3107, https://doi.org/10.1088/0022-3719/10/16/019
F. D. Murnaghan, The compressibility of media under extreme pressures, Proceedings of the National Academy of Sciences 30 (1944) 244, https://doi.org/10.1073/pnas.30.9.244
H. Alqurashi, R. Haleoot, and B. Hamad, First-principles investigations of the electronic, magnetic and thermoelectric properties of VTiRhZ (Z= Al, Ga, In) Quaternary Heusler alloys, Materials Chemistry and Physics 278 (2022) 125685, https://doi.org/10.1016/j.matchemphys.2021.125685
G. Forozani et al., Structural, electronic and magnetic properties of CoZrIrSi quaternary Heusler alloy: First-principles study, Journal of Alloys and Compounds 815 (2020) 152449, https://doi.org/10.1016/j.jallcom.2019.152449
J. Jami et al., First-principles investigation of the structure, stability, and magnetic properties of the Heusler alloy Fe 2 MnSn, Physical Review B 108 (2023) 054431, https://doi.org/10.1103/PhysRevB.108.054431
H. Alqurashi and B. Hamad, Magnetic structure, mechanical stability and thermoelectric properties of VTiRhZ (Z= Si, Ge, Sn) quaternary Heusler alloys: First-principles calculations, Applied Physics A 127 (2021) 799, https://doi.org/10.1007/s00339-021-04949-0
M. Benidris et al., Electronic structure, thermoelectric, mechanical and phonon properties of full-Heusler alloy (Fe 2 CrSb): a first-principles study, Bulletin of Materials Science 44 (2021) 1, https://doi.org/10.1007/s12034-021-02496-1
D. Hoat, Structural, optoelectronic and thermoelectric properties of antiperovskite compounds Ae3PbS (Ae= Ca, Sr and Ba): a first principles study, Physics Letters A 383 (2019) 1648, https://doi.org/10.1016/j.physleta.2019.02.013
P. K. Kamlesh et al., Investigation of inherent properties of XScZ (X= Li, Na, K; Z= C, Si, Ge) half-Heusler compounds: appropriate for photovoltaic and thermoelectric applications, Physica B: Condensed Matter 615 (2021) 412536, https://doi.org/10.1016/j.physb.2020.412536
D. Shrivastava and S. P. Sanyal, Theoretical study of structural, electronic, phonon and thermoelectric properties of KScX (X= Sn and Pb) and KYX (X= Si and Ge) half-Heusler compounds with 8 valence electrons count, Journal of Alloys and Compounds 784 (2019) 319, https://doi.org/10.1016/j.jallcom.2019.01.050
M. Holland, Analysis of lattice thermal conductivity, Physical review 132 (1963) 2461, https://doi.org/10.1103/PhysRev.132.2461
A. Amudhavalli et al., First principles study of structural and optoelectronic properties of Li based half Heusler alloys, Computational Condensed Matter 14 (2018) 55, https://doi.org/10.1016/j.cocom.2018.01.002
P. Larson et al., Electronic structure of rare-earth nickel pnictides: Narrow-gap thermoelectric materials, Physical Review B 59 (1999) 15660, https://doi.org/10.1103/PhysRevB.59.15660
M. Naseri and D. Hoat, First principles investigation on elastic, optoelectronic and thermoelectric properties of KYX (X= Ge, Sn and Pb) half-heusler compounds, Journal of Molecular Graphics and Modelling 92 (2019) 249, https://doi.org/10.1016/j.jmgm.2019.08.002
G. K. Madsen, J. Carrete, and M. J. Verstraete, BoltzTraP2, a program for interpolating band structures and calculating semiclassical transport coefficients, Computer Physics Communications 231 (2018) 140, https://doi.org/10.1016/j.cpc.2018.05.010
C. Han, Z. Li, and S. Dou, Recent progress in thermoelectric materials, Chinese science bulletin 59 (2014) 2073, https://doi.org/10.1007/s11434-014-0237-2
B. Anissa, D. Radouan, and I. K. Durukan, Study of structural, electronic, elastic, optical and thermoelectric properties of half-Heusler compound RbScSn: A TB-mBJ DFT study, Optical and Quantum Electronics 54 (2022) 372, https://doi.org/10.1007/s11082-022-03780-y
J. Zhang et al., Phosphorene nanoribbon as a promising candidate for thermoelectric applications, Scientific reports 4 (2014) 6452, https://doi.org/10.1038/srep06452
N. Chami et al., Computational prediction of structural, electronic, elastic, and thermoelectric properties of FeV X (X= as, P) half-heusler compounds, Journal of Electronic Materials 49 (2020) 4916, https://doi.org/10.1007/s11664-020-08225-4
A. Reshak and S. Auluck, Thermoelectric properties of nowotny-juza NaZnX (X= P, as and Sb) compounds, Computational Materials Science 96 (2015) 90, https://doi.org/10.1016/j.commatsci.2014.09.008
M.-S. Lee, F. P. Poudeu, and S. Mahanti, Electronic structure and thermoelectric properties of Sb-based semiconducting halfHeusler compounds, Physical Review B-Condensed Matter and Materials Physics 83 (2011) 085204, https://doi.org/10.1103/PhysRevB.83.085204
M. K. Yadav and B. Sanyal, First-principles study of thermoelectric properties of CuI, Materials Research Express 1 (2014) 015708, https://doi.org/10.1088/2053-1591/1/ 1/015708
D. J. Singh, Doping-dependent thermopower of PbTe from Boltzmann transport calculations, Physical Review B-Condensed Matter and Materials Physics 81 (2010) 195217, https://doi.org/10.1103/PhysRevB.81.195217
G. A. Slack, The thermal conductivity of nonmetallic crystals, Solid state physics 34 (1979) 1, https://doi.org/10.1016/S0081-1947(08)60359-862
R. Farris et al., Giant thermoelectric figure of merit in multivalley high-complexity-factor LaSO, Physical Review Materials 5 (2021) 125406, https://doi.org/10.1103/PhysRevMaterials.5.125406
J. Kangsabanik, A. Alam et al., Bismuth based half-Heusler alloys with giant thermoelectric figures of merit, Journal of Materials Chemistry A 5 (2017) 6131, https://doi.org/10.1039/C7TA00920H
S. Guo et al., Prediction of improved thermoelectric performance by ordering in double half-Heusler materials, Journal of Materials Chemistry A 8 (2020) 23590, https://doi.org/10.1039/D0TA08364J
Downloads
Published
How to Cite
Issue
Section
License
Copyright (c) 2026 Y. Al-Douri
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
Authors retain copyright and grant the Revista Mexicana de Física right of first publication with the work simultaneously licensed under a CC BY-NC-ND 4.0 that allows others to share the work with an acknowledgement of the work's authorship and initial publication in this journal.
