Exploring the electronic, magnetic and thermoelectric properties of TbPtBi half-Heusler: DFT Study

In this investigation, we employed density functional theory (DFT) to scrutinize the structural, electronic, magnetic, thermoelectric, and phonon properties of the topological half-Heusler (HH) TbPtBi compound. The stable phonon dispersion spectrum affirms the dynamical stability of the compound. The inclusion of Spin-orbit coupling (SOC) significantly influenced the compound's electronic and thermoelectric properties. The density of state (DOS) confirmed the impact of SOC on the topologically non-trivial metallic behavior of TbPtBi under the equilibrium lattice constant. The SOC altered the DOS at the Fermi level, leading to band splitting and a notable 70% reduction in state density. The Tb-4f electrons in the compound induce total magnetization in AFM (-5.93 µB/cell) and FM (5.94 µB/cell) phases, while SOC eliminates this magnetization. The thermoelectric performance of TbPtBi under compressive and tensile strain has been systematically studied. The result indicates that compressive strain causes a notable increment in the Seebeck coefficient and Power factor (20.4 × 1011W/K2m) of this compound at room temperature. High thermoelectric performance under compressive strain in the HH compound TbPtBi might open new avenues for investigating other topological thermoelectric materials.