Half-metallicity (HM) offers great potential for engineering spintronic applications, yet only few magnetic materials present metallicity in just one spin channel. In addition, most HM systems become magnetically disordered at temperatures well below ambient conditions, which further hinders the development of spin-based electronic devices. Here, we use first-principles methods based on density functional theory (DFT) to investigate the electronic, magnetic, structural, mixing, and vibrational properties of 90 XYZ half-Heusler (HH) alloys (X = Li, Na, K, Rb, Cs; Y = V, Nb, Ta; Z = Si, Ge, Sn, S, Se, Te). We disclose a total of 28 new HH compounds that are ferromagnetic, vibrationally stable, and HM, with semiconductor band gaps in the range of 1–4 eV and HM band gaps of 0.2–0.8 eV. By performing Monte Carlo simulations of a spin Heisenberg model fitted to DFT energies, we estimate the Curie temperature, TC, of each HM compound. We find that 17 HH HM remain magnetically ordered at and above room temperature, namely, 300 ≤ TC ≤ 450 K, with total magnetic moments of 2 and 4 μB. A further materials sieve based on zero-temperature mixing energies let us to conclude 5 overall promising HH HM that remain magnetically ordered at and above room temperature: NaVSi, RbVTe, CsVS, CsVSe, and RbNbTe. We also predict 2 semiconductor materials that are ferromagnetic at ambient conditions: LiVSi and LiVGe.
Felser C, Fecher GH, Balke B. Spintronics: a challenge for materials science and solid-state chemistry. Angew Chem Int Ed 2007;46:668
Zutic I, Fabian J, Sarma SD. Spintronics: fundamentals and applications. Rev Mod Phys 2003;76:323
Zhu H, et al. Discovery of TaFeSb-based half-heuslers with high thermoelectric performance. Nat Commun 2019;10:270
Bhat SG, Anil Kumar PS. Demonstration of efficient spin injection and detection in various systems using Fe3O4 based spin injectors. AIP Adv 2016;6:056308
Dash SP, Sharma S, Patel RS, de Jong MP, Jansen R. Electrical creation of spin polarization in silicon at room temperature. Nature 2009;462:491
Tanaka CT, Nowak J, Moodera JS. Spin-polarized tunneling in a half-metallic ferromagnet. J Appl Phys 1999;86:6239
Hordequin C, Nozieres J, Pierre J. Half metallic NiMnSb-based spin-valve structures. J Magn Magn Mater 1998;183:225
de Groot RA, Mueller FM, van Engen PG, Buschow KHJ. New class of materials: half-metallic ferromagnets. Phys Rev Lett 1983;50:2024
Casper F, Graf T, Chadov S, Balke B, Felser C. Half-heusler compounds: novel materials for energy and spintronic applications. Semicond Sci Technol 2012;27:063001
Azadani JG, Munira K, Romero J, Ma J, Sivakumar C, Ghosh AW, et al. Anisotropy in layered half-metallic heusler alloy superlattices. J Appl Phys 2016;119:043904
Cazorla C, Boronat J. Simulation and understanding of atomic and molecular quantum crystals. Rev Mod Phys 2017;89:035003
Damewood L, Busemeyer B, Shaughnessy M, Fong CY, Yang LH, Felser C. Stabilizing and increasing the magnetic moment of half-metals: the role of Li in half-heusler LiMnZ (Z = N,P,Si). Phys Rev B 2015;91:064409
Ma J, Hegde VI, Munira K, Xie Y, Keshavarz S, Mildebrath DT, et al. Computational investigation of half-heusler compounds for spintronics applications. Phys Rev B 2017;95:024411
Legrain F, Carrete J, van Roekeghem A, Madsen GKH, Mingo N. Materials screening for the discovery of new half-heuslers: machine learning versus ab initio methods. J Phys Chem B 2018;122:625
Sattar MA, Rashid M, Hussain F, Imran M, Hashmi MR, Laref A, et al. Physical properties of half-heusler YMnZ (Z=Si,Ge,Sn) compounds via ab-initio study. Solid State Commun 2018;278:10
Tu NT, Hai PN, Anh LD, Tanaka M. High-temperature ferromagnetism in heavily Fe-doped ferromagnetic semiconductor (Ga,Fe)Sb. Appl Phys Lett 2016;108:192401
Cao Q, Fu M, Zhu D, Yao M, Hu S, Chen Y, et al. Growth-controlled engineering of magnetic exchange interactions in single crystalline GaCoZnO1-v epitaxial films with high Co concentration. Chem Mater 2017;29:2717
Curtarolo S, Hart GLW, Nardelli MB, Mingo N, Sanvito S, Levy O. The high-throughput highway to computational materials design. Nat Mater 2013;12:191
Galanakis I, Mavropoulos Ph, Dederichs PH. Electronic structure and SlaterPauling behaviour in half-metallic heusler alloys calculated from first principles. J Phys D: Appl Phys 2006;39:765
Wei X-P, Deng J-B, Mao G-Y, Chu S-B, Hu X-R. Half-metallic properties for the Ti2YZ (Y = Fe,Co,Ni; Z = Al,Ga,in) heusler alloys: a first-principles study. Intermetallics 2012;29:86
van Leuken H, de Groot RA. Half-metallic antiferromagnets. Phys Rev Lett 1994;74:1171
Luo HZ, Zhang HW, Zhu ZY, Ma L, Xu SF, Wu GH, et al. Half-metallic properties for the Mn2FeZ (Z = Al,Ga,Si,Ge,Sb) heusler alloys: a first-principles study. J Appl Phys 2008;103:083908
Hu X. HalfMetallic antiferromagnet as a prospective material for spintronics. Adv Mater 2011;24:294
Hussain MK. Investigations of the electronic and magnetic properties of newly (001) surface LiCrS and LiCrSe half-heusler compounds. Appl Phys A 2018;124:343
Wang X, Cheng Z, Liu G. Largest magnetic moments in the half-heusler alloys XCrZ (X = Li,K,Rb,Cs; Z = S,Se,Te): a first-principles study. Materials 2017;10:1078
Graf T, Felser Cl, Parkin SSP. Simple rules for the understanding of heusler compounds. Prog Solid State Chem 2011;39:1
Blaha, P.; Schwarz, K.; Madsen, G. K. H.; Kvasnicka, D.; Luitz, J.; Laskowski, R.; et al. WIEN2k, an augmented plane wave + local orbitals program for calculating crystal properties, karlheinz schwarz, techn. Universität Wien 2018, Austria, ISBN:3-9501031-1-2.
Perdew JP, Burke K, Ernzerhof M. Generalized gradient approximation made simple. Phys Rev Lett 1996;77:3865
Tran F, Blaha P. Accurate band gaps of semiconductors and insulators with a semilocal exchange-correlation potential. Phys Rev Lett 2009;102:226401
Kresse G, Fürthmuller J. Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set. Phys Rev B 1996;54:11169
Blöchl PE. Projector augmented-wave method. Phys Rev B 1994;50:17953
Alfè D. PHON: a program to calculate phonons using the small displacement method. Comput Phys Commun 2009;180:2622
Togo A, Tanaka I. First principles phonon calculations in materials science. Scripta Mater 2015;108:1
Singh A, Mohapatra S, Ziman T, Chatterji T. Spin waves in the FCC lattice antiferromagnet: competing interactions, frustration, and instabilities in the hubbard model. J Appl Phys 2017;121:073903
Escorihuela-Sayalero C, Diéguez O, Íñiguez J. Strain engineering magnetic frustration in perovskite oxide thin films. Phys Rev Lett 2012;109:247202
Cazorla C, Íñiguez J. Insights into the phase diagram of bismuth ferrite from quasiharmonic free-energy calculations. Phys Rev B 2013;88:214430
Cazorla C, Diéguez O, Íñiguez J. Multiple structural transitions driven by spin-phonon couplings in a perovskite oxide. Sci. Adv. 2017;3:e1700288
Cazorla C, Íñiguez J. Giant direct and inverse electrocaloric effects in multiferroic thin films. Phys Rev B 2018;98:174105
Cazorla C, Boronat J. First-principles modeling of quantum nuclear effects and atomic interactions in solid 4He at high pressure. Phys Rev B 2015;91:024103
Rost CM, Sachet E, Borman T, Moballegh A, Dickey EC, Hou D, et al. Entropy-stabilized oxides. Nat Commun 2015;6:8485
Benisek A, Dachs E. The vibrational and configurational entropy of disordering in Cu3Au. J Alloy Comp 2015;632:585
Shenoy JN, Hart JN, Grau-Crespo R, Allan NL, Cazorla C. Mixing thermodynamics and photocatalytic properties of GaP-ZnS solid solutions. Adv. Theory Simul. 2019;2:1800146
van de Walle A, Ceder G. The effect of lattice vibrations on substitutional alloy thermodynamics. Rev Mod Phys 2002;74:11
Bhattacharya S, Madsen GKH. A novel P-type half-heusler from high-throughput transport and defect calculations. J Mater Chem C 2016;4:11261
Page A, Poudeu PFP, Uher C. A first-principles approach to half-heusler thermoelectrics: accelerated prediction and understanding of material properties. J. Materiomics 2016;2:104
Rogl G, et al. (V,Nb)-Doped half heusler alloys based on (Ti,Zr,Hf)NiSn with high ZT. Acta Mater 2017;131:336