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Title: Designing High-Efficiency Nanostructured Two-Phase Heusler Thermoelectrics

Abstract

Nanostructured systems formed by two distinct phases are particularly promising for high efficiency thermoelectrics due to the reduction in thermal conductivity afforded by the nanostructured phase. However, the choice of the matrix and nanostructured phases represents a challenging materials discovery problem due to the large compositional space involved. Heusler phase thermoelectrics are particularly promising candidates for nanostructuring since these compounds often possess favorable electronic thermoelectric properties but relatively high thermal conductivity. Here, we have developed a high-throughput screening strategy to predict promising candidates for nanostructuring systems based on two Heusler phases. Our search includes all two-phase systems involving full, half, and inverse Heusler in the Open Quantum Materials Database, in total a search space of ~1011 possible combinations of two Heusler compounds. To reduce this space, our screening approach starts with a set of known thermoelectrics as matrix phases and screens for all second phase compounds that are stable and form a two-phase equilibrium with the matrix. We compute mixing energies for the resulting combinations of a matrix and a nanostructured phase, find systems that have a moderately large positive mixing energy, and hence show an appropriate balance between tendency for nanostructuring and solubility of the second phase. Our screeningmore » approach gives 31 pairs, two of which have been explored experimentally (thus validating our screening strategy) and 29 of which represent new predictions of systems awaiting experimental synthesis. In addition, our results show that matrix/nanostructure pairs consisting of distinct crystal structures (e.g., mixing of half Heusler with full Heusler) typically have low mutual solubility, whereas isostructural matrix/nanostructured phase pairs (where both matrix and nanostructure have the same structure type, half Heusler or full Heusler) more often have energetics suitable for forming nanostructures or solid solutions.« less

Authors:
ORCiD logo [1]; ORCiD logo [1]
  1. Department of Materials Science and Engineering, Northwestern University, Evanston, Illinois 60208, United States
Publication Date:
Research Org.:
Lawrence Berkeley National Laboratory-National Energy Research Scientific Computing Center
Sponsoring Org.:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
OSTI Identifier:
1480069
DOE Contract Number:  
SC0014520
Resource Type:
Journal Article
Journal Name:
Chemistry of Materials
Additional Journal Information:
Journal Volume: 29; Journal Issue: 21; Journal ID: ISSN 0897-4756
Publisher:
American Chemical Society (ACS)
Country of Publication:
United States
Language:
English

Citation Formats

Kocevski, Vancho, and Wolverton, Chris. Designing High-Efficiency Nanostructured Two-Phase Heusler Thermoelectrics. United States: N. p., 2017. Web. doi:10.1021/acs.chemmater.7b03379.
Kocevski, Vancho, & Wolverton, Chris. Designing High-Efficiency Nanostructured Two-Phase Heusler Thermoelectrics. United States. doi:10.1021/acs.chemmater.7b03379.
Kocevski, Vancho, and Wolverton, Chris. Tue . "Designing High-Efficiency Nanostructured Two-Phase Heusler Thermoelectrics". United States. doi:10.1021/acs.chemmater.7b03379.
@article{osti_1480069,
title = {Designing High-Efficiency Nanostructured Two-Phase Heusler Thermoelectrics},
author = {Kocevski, Vancho and Wolverton, Chris},
abstractNote = {Nanostructured systems formed by two distinct phases are particularly promising for high efficiency thermoelectrics due to the reduction in thermal conductivity afforded by the nanostructured phase. However, the choice of the matrix and nanostructured phases represents a challenging materials discovery problem due to the large compositional space involved. Heusler phase thermoelectrics are particularly promising candidates for nanostructuring since these compounds often possess favorable electronic thermoelectric properties but relatively high thermal conductivity. Here, we have developed a high-throughput screening strategy to predict promising candidates for nanostructuring systems based on two Heusler phases. Our search includes all two-phase systems involving full, half, and inverse Heusler in the Open Quantum Materials Database, in total a search space of ~1011 possible combinations of two Heusler compounds. To reduce this space, our screening approach starts with a set of known thermoelectrics as matrix phases and screens for all second phase compounds that are stable and form a two-phase equilibrium with the matrix. We compute mixing energies for the resulting combinations of a matrix and a nanostructured phase, find systems that have a moderately large positive mixing energy, and hence show an appropriate balance between tendency for nanostructuring and solubility of the second phase. Our screening approach gives 31 pairs, two of which have been explored experimentally (thus validating our screening strategy) and 29 of which represent new predictions of systems awaiting experimental synthesis. In addition, our results show that matrix/nanostructure pairs consisting of distinct crystal structures (e.g., mixing of half Heusler with full Heusler) typically have low mutual solubility, whereas isostructural matrix/nanostructured phase pairs (where both matrix and nanostructure have the same structure type, half Heusler or full Heusler) more often have energetics suitable for forming nanostructures or solid solutions.},
doi = {10.1021/acs.chemmater.7b03379},
journal = {Chemistry of Materials},
issn = {0897-4756},
number = 21,
volume = 29,
place = {United States},
year = {2017},
month = {10}
}