Journal Article

FZJ-2019-06545

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Ag-Segregation to Dislocations in PbTe-Based Thermoelectric Materials

Yu, Y. ; Zhang, S. ; Mio, A. M. ; Gault, B. ; Sheskin, A. ; Scheu, C. ; Raabe, D. ; Zu, F. ; Wuttig, M. (Corresponding author)FZJ* ; Amouyal, Y. ; Cojocaru-Mirédin, O.

2018
Soc. Washington, DC

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Please use a persistent id in citations: doi:10.1021/acsami.7b17142

Abstract: Dislocations have been considered to be an efficient source for scattering midfrequency phonons, contributing to the enhancement of thermoelectric performance. The structure of dislocations can be resolved by electron microscopy whereas their chemical composition and decoration state are scarcely known. Here, we correlate transmission Kikuchi diffraction and (scanning) transmission electron microscopy in conjunction with atom probe tomography to investigate the local structure and chemical composition of dislocations in a thermoelectric Ag-doped PbTe compound. Our investigations indicate that Ag atoms segregate to dislocations with a 10-fold excess of Ag compared with its average concentration in the matrix. Yet the Ag concentration along the dislocation line is not constant but fluctuates from ∼0.8 to ∼10 atom % with a period of about 5 nm. Thermal conductivity is evaluated applying laser flash analysis, and is correlated with theoretical calculations based on the Debye–Callaway model, demonstrating that these Ag-decorated dislocations yield stronger phonon scatterings. These findings reduce the knowledge gap regarding the composition of dislocations needed for theoretical calculations of phonon scattering and pave the way for extending the concept of defect engineering to thermoelectric materials.

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Contributing Institute(s):

1. JARA Institut Green IT (PGI-10)

Research Program(s):

1. 521 - Controlling Electron Charge-Based Phenomena (POF3-521) (POF3-521)

Appears in the scientific report 2019

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Database coverage:
; Clarivate Analytics Master Journal List ; Current Contents - Engineering, Computing and Technology ; Current Contents - Physical, Chemical and Earth Sciences ; IF >= 5 ; JCR ; NCBI Molecular Biology Database ; SCOPUS ; Science Citation Index ; Science Citation Index Expanded ; Web of Science Core Collection

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