Computational Investigation of Half-Heusler Compounds for Spintronics Applications

Abstract

We present first-principles density functional calculations of the electronic structure, magnetism, and structural stability of 378 $\text{XYZ}$ half-Heusler compounds (with $X=$ Cr, Mn, Fe, Co, Ni, Ru, Rh, $Y=$ Ti, V, Cr, Mn, Fe, Ni, $Z=$ Al, Ga, In, Si, Ge, Sn, P, As, Sb). We find that a "Slater-Pauling density of states" with a gap or pseudogap at three states per atom below the gap in at least one spin channel is a common feature in half-Heusler compounds. We find that the presence of such a gap at the Fermi energy in one or both spin channels contributes greatly to the stability of a half-Heusler compound. We calculate the formation energy of each compound and systematically investigate its stability against all other phases in the Open Quantum Materials Database (OQMD). We represent the thermodynamic phase stability of each compound as its distance from the convex hull of stable phases in the respective chemical space and show that the hull distance of a compound is a good measure of the likelihood of its experimental synthesis. We identify 26 18-electron semiconductors, 45 half-metals, and 34 near half-metals with negative formation energy, that follow the Slater-Pauling rule of three electrons per atom. Our calculations predict new thermodynamically stable semiconducting phases NiScAs, RhTiP, and RuVAs, which merit further experimental exploration. Further, two interesting zero-moment half-metals, CrMnAs and MnCrAs, are calculated to have negative formation energy. In addition, our calculations predict a number of new, hitherto unreported, semiconducting (e.g., CoVGe, FeVAs), half-metallic (e.g., RhVSb), near half-metallic (e.g., CoFeSb, CoVP) half-Heusler compounds to lie close to the respective convex hull of stable phases, and thus may be experimentally realized under suitable synthesis conditions, resulting in potential candidates for various spintronics applications.

27 pages, 19 figures

References in corpus (6)

• Half-metallic ferromagnets: From band structure to many-body effects
• Covalent bonding and the nature of band gaps in some half-Heusler compounds
• Half-Heusler Topological Insulators: A First-Principle Study with the Tran-Blaha Modified Becke-Johnson Density Functional
• Large Noncollinearity and Spin Reorientation in the Novel Mn2RhSn Heusler Magnet
• Exchange interactions and Curie temperatures in Mn2CoZ compounds
• New High-$T_c$ Half-Heusler Ferromagnets NiMnZ (Z = Si, P, Ge, As)

Cited by in corpus (11)

• Prediction of half-metallicity and spin-gapless semiconducting behavior in the new series of FeCr-based quaternary Heusler alloys: an ab initio study
• Theoretical study of the structural stability, electronic and magnetic properties of XVSb (X $=$ Fe, Ni, and Co) half-Heusler compounds
• Effect of doping on SGS and weak half-metallic properties of inverse Heusler Alloys
• Ab initio design of quaternary Heusler compounds for reconfigurable magnetic tunnel diodes and transistors
• Growth, electrical, structural, and magnetic properties of half-Heusler CoTi${}_{1-x}$Fe${}_x$Sb
• A strategic high throughput search for identifying stable Li based half Heusler alloys for spintronics applications
• Formation of two-dimensional electron and hole gases at the interface of half-Heusler semiconductors
• Spin and current transport in the robust half-metallic magnet $c$-CoFeGe
• Electronic structure and thermoelectric properties of CoTiSi half-Heusler alloy: Doping overtones
• An Enormous Class of Double Half-Heusler Compounds with Low Thermal Conductivity
• Inducing half metallicity with alloying in Heusler Compound CoFeMnSb