@article{10902/31594,
year = {2021},
month = {1},
url = {https://hdl.handle.net/10902/31594},
abstract = {PbTe is a leading thermoelectric material at intermediate temperatures, largely thanks to its low lattice thermal conductivity. However, its efficiency is too low to compete with other forms of power generation. This efficiency can be effectively enhanced by designing nanostructures capable of scattering phonons over a wide range of length scales to reduce the lattice thermal conductivity. The presence of grain boundaries can reduce the thermal conductivity to -0.5Wm-1K-1 for small vacancy concentrations and grain sizes. However, grains anneal at finite temperature, and equilibrium and metastable grain size distributions determine the extent of the reduction in thermal conductivity. In the present work, we propose a phase-field model informed by molecular dynamics simulations to study the annealing process in PbTe and how it is affected by the presence of grain boundaries and voids. We find that the thermal conductivity of PbTe is reduced by up to 35% in the porous material at low temperatures. We observe that a phase transition at a finite density of voids governs the kinetics of impeding grain growth by Zener pinning.},
organization = {This work was supported by a research grant from Science Foundation Ireland (SFI) and the Department for the Economy Northern Ireland under the SFI-DfE Investigators Programme Partnership, Grant No. 15/IA/3160. We are grateful for computational support from the UK national high-performance computing service, ARCHER, for which access was obtained via the UKCP consortium and funded by EPSRC Grant Ref. EP/P022561/1, and from the UK Materials and Molecular Modelling Hub, which was partially funded by EPSRC Grant Ref. EP/P020194/1. We thank Adrian P. Sutton, Michael W. Finnis, and Lorenzo Stella for insightful discussions.},
publisher = {American Physical Society},
publisher = {Physical Review Materials, 2021, 5(1), 014604},
title = {Thermal conductivity of porous polycrystalline PbTe},
author = {Troncoso, Javier F. and Chudzinski, Piotr and Todorov, Tchavdar N. and Aguado Puente, Pablo and Grüning, Myrta and Kohanoff, Jorge J.},
}