AVS 64th International Symposium & Exhibition
    Electronic Materials and Photonics Division Monday Sessions
       Session EM+MI+TF-MoM

Paper EM+MI+TF-MoM6
Computational Investigation of Heusler Compoundss for Spintronic Applications

Monday, October 30, 2017, 10:00 am, Room 14

Session: Growth, Electronic, and Magnetic Properties of Heusler Compounds
Presenter: Jianhua Ma, University of Virginia
Authors: J. Ma, University of Virginia
W.H. Butler, University of Alabama
Correspondent: Click to Email
We present first-principles density functional calculations of the electronic structure, magnetism, and structural stability of 378 XYZ half-Heusler, 405 X2YZ inverse-Heusler, 576 X2YZ full-Heusler compounds. We find that a “Slater-Pauling gap” in the density of states in at least one spin channel is a common feature in Heusler compounds. We find that the presence of such a gap at the Fermi energy in one or both spin channels contributes significantly to the stability of a 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 find low formation energies and mostly correspondingly low hull distances for compounds with X = Co, Rh, or Ni, Y = Ti or V, and Z = P, As, Sb, or Si in half-Heulser compounds. In the half-Heusler family, 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. In the inverse-Heusler family, we identify 14 asymmetric 18-electron semiconductors, 50 half-metals, and 42 near half-metals with negative formation energy. In the full-Heusler family, we identify 8 24-electron semiconductors and 23 half-metals with negative formation energy. Our calculations predict several new, as-yet unknown, thermodynamically stable phases, which merit further experimental exploration—RuVAs, CoVGe, FeVAs in the half-Heusler structure, and NiScAs, RuVP, RhTiP in the orthorhombic MgSrSi-type structure. 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 hitherto unreported semiconducting (e.g., CoVSn and RhVGe), half-metallic (e.g., RhVSb), and near half-metallic (e.g., CoFeSb and 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 semiconducting and spintronics applications.