Electronic, Elastic, and Thermoelectric Properties of Half-Heusler Topological Semi-Metal HfIrAs from First-Principles Calculations

Abstract

The ab initio method is used to calculate the electronic, elastic, lattice-dynamic, and thermoelectric properties of the semimetal Half-Heusler compound HfIrAs. Density Functional Theory within Generalized Gradient Approximation is used to carry out calculations of lattice parameters, band structure, electronic density of states, phonon band structure, phonon density of states, elastic moduli, specific heat at constant volume, the Seebeck coefficient, electrical conductivity, the power factor, and the dimensionless figure of merit. The electronic band structure reveals that the compound is semimetal. The phonon dispersion shows that HfIrAs is dynamically stable. The projected phonon density of states, which shows the contribution of each constituent atom at every frequency level, is also reported. The ratio of bulk modulus to shear modulus is 2.89; i.e., the material is ductile, and it satisfies stability criteria. The thermoelectric properties of this compound at different temperatures of 300 K, 600 K, and 800 K are reported as a function of hole concentration for the first time to the best of our knowledge. The dimensionless figure of merit of HfIrAs is 0.57 at 800 K when the doping concentration is 0.01×1020 cm−3. Therefore, this compound is predicted to be a good thermoelectric material.

Strain-tunable electronic structure, optical and thermoelectric properties of BAs

“…Analyzing the elastic constants C ij of materials is an effective method to obtain their mechanical properties [31]. For cubic BAs, they are judged to be mechanically stable when C 11 > 0, C 44 > 0, C 11 -C 12 > 0, C 11 +2C 12 > 0, and C 12 < B < C 11 are satisfied [23,32].…”

Defect-induced modifications in electronic and thermoelectric properties of pentagonal PdX2 (X = Se, S) monolayers

“…Many classes of materials have been proposed and studied in literature under the influence of point defects on their electronic [22], optical [23], and transport properties have been studied. These materials include heusler alloys [24][25][26][27], clathrates, skutterudites and two-dimensional chalcogenide materials. In two-dimensional (2D) materials, the structural defects that are likely to appear are generally of the form of point defects or edges [28][29][30].…”

Magnetic States and Electronic Properties of Manganese-Based Intermetallic Compounds Mn2YAl and Mn3Z (Y = V, Cr, Fe, Co, Ni; Z = Al, Ge, Sn, Si, Pt)

“…Heusler compounds, discovered over 100 years ago by German chemist F. Heusler [1], continue to be a subject of great interest in current research. These compounds exhibit a wide range of unique multifunctional properties [2], such as half-metallic ferromagnetism [3][4][5], spin gapless semiconductor state [6][7][8], topological insulator and semimetal behavior [8][9][10][11], shape memory effect [12,13], magnetocaloric effect [14,15], and many others (see, for example, refs. [2,16,17] and references therein).…”