Lowering thermal conductivity in thermoelectric Ti2−xNiCoSnSb half Heusler high entropy alloys

High-Entropy Engineering in Thermoelectric Materials: A Review

“…Figure 11b shows the enthalpy of formation of high-entropy thermoelectric materials (Ti 2 NiCoSnSb and Ti 1 . 5 NiCoSnSb) and other related compounds using Equation ( 5) for the high-entropy and hH TE materials determined using DFT calculations [82].…”

“…This makes DFT calculations computationally intensive and demands higher computing power. Figure 11b shows the enthalpy of formation of high-entropy thermoelectric materials (Ti2NiCoSnSb and Ti1.5NiCoSnSb) and other related compounds using Equation ( 5) for the high-entropy and hH TE materials determined using DFT calculations [82]. Thermodynamic properties can be computed as a function of temperature using quasi-harmonic approximation (QHA) [83], which evaluates the volume dependence of phonon frequencies in a structure consisting of vibrating atoms.…”

High-entropy materials for thermoelectric applications: towards performance and reliability

“…125,165 Mishra et al synthesized a HH-HEM, denoted as Ti 2− x NiCoSnSb ( x = 0.125, 0.25, 0.375, and 0.5), using the arc melting, ball milling, and SPS techniques. 167 They found that reducing the Ti content led to an increase in the formation of Ni-rich intermetallic compounds (Ni 3 Sn 2 and Ni 3 Sn 4 ) and Ni-rich full-Husler (TiNiSn) as secondary phases in the HEM. σ increased, while the lattice k decreased due to the higher concentrations of secondary phases.…”

Half-Heusler based multicomponent alloys for high temperature thermoelectric applications

“…2.7 First principles analysis 7. 3 Future (Sun et al, 2022), (b) and (c) mechanical properties (Nandihalli, 2022;Rogl et al, 2016) of TE materials, and (d) cost per Kg analysis (Liu et al, 2018) of TE raw materials for synthesis.…”

“…Samples A (q = 0.1), B (q = 0.5), C (q = 1.0), and D (x = y = q = 0.5) are depicted as red circles, blue triangles, pink inverse triangles, and green diamonds, respectively. 1) TiNiSn (Karati et al, 2019a), ( 2) TiCoSb (Chauhan et al, 2019a), (3) ZrCoSb , (4) Ti2NiCoSnSb (Karati et al, 2019b), (5) Ti2NiCoSn0.5Sb1.5 , (6) TiZrNiCoSnSb, (7) TiZrNiCoSn0.5Sb1.5, (8) TiTaNiCoSn0.5Sb1.5, (9) TiAlNiCoSn0.5Sb1.5, (10) (TiTaAl)NiCoSn0.5Sb1.5, (11) (TiTaAlZr)NiCoSn0.5Sb1.5, and (12) (Ti1.6Ta0.2Al0.2)NiCoSn0.5Sb1.5, respectively. 5.9 Phase and composition analysis of Ti2-x-yAlxTayNiCoSn0.5Sb1.5 VAM alloys (n=4).…”