Investigation of the Structural, Electronic, Elastic, Thermodynamic, and Thermoelectric Properties of HfXPb (X = Ni, Pd, Pt): First-Principles Study

The 18-valence electron ABX families of compounds have a variety of attractive physical properties. In this work, using the (FP-L/APW + lo) method on the basis of density functional theory, we have investigated the structural, electronic, elastic, thermodynamic, and transport properties of the HfXPb (X = Ni, Pd, Pt), in the cubic half-Heusler LiAlSi-type (F-43m) structure. The calculated elastic constants for these compounds showed that they are mechanically stable. Considering the Tran–Blaha-modified Becke–Johnson potential which provides a better description of the electronic structures, we have found that all three compounds are narrow-gap semiconductors. Furthermore, the thermoelectric properties depending on the chemical potential and charge carrier densities at different temperatures, 300 K, 600 K, and 900 K, are thus evaluated from the semi classical Boltzmann transport equation. The lattice thermal conductivity has been calculated by using a simplified model. Moreover, the most important thermodynamic properties, such as the Debye temperature, the thermal expansion coefficient, the heat capacity, and the entropy, have been predicted.