Attaining Low Lattice Thermal Conductivity in Half-Heusler Sublattice Solid Solutions: Which Substitution Site Is Most Effective?

Low thermal conductivity is an important materials property for thermoelectricity. The lattice (LTC) can be reduced by introducing sublattice disorder through partial isovalent substitution. Yet, large-scale screening of has seldom taken this opportunity into account. present study aims to investigate the effect substitution on LTC. relies temperature-dependent effective potential method based forces obtained from density functional theory. Solid solutions are simulated within a virtual crystal approximation, and grain-boundary scattering also included. This done systematically probe LTC 122 half-Heusler compounds. It found that three different crystallographic sites leads reduction varies significantly both between Nevertheless, some common criteria identified as most efficient LTC: mass contrast should large parent compound, performed heaviest atoms. combined lead drastic lowest current set compounds around 2 W/Km at 300 K two Four additional reach similarly low with grain boundaries. Two these four have intrinsic above ∼15 W/Km, underlining high could still viable thermoelectric applications.