TY  - JOUR
AU  - Yu, Yuan
AU  - Zhang, Siyuan
AU  - Mio, Antonio Massimiliano
AU  - Gault, Baptiste
AU  - Sheskin, Ariel
AU  - Scheu, Christina
AU  - Raabe, Dierk
AU  - Zu, Fangqiu
AU  - Wuttig, Matthias
AU  - Amouyal, Yaron
AU  - Cojocaru-Mirédin, Oana
TI  - Ag-Segregation to Dislocations in PbTe-Based Thermoelectric Materials
JO  - ACS applied materials & interfaces
VL  - 10
IS  - 4
SN  - 1944-8252
CY  - Washington, DC
PB  - Soc.
M1  - FZJ-2019-06545
SP  - 3609 - 3615
PY  - 2018
AB  - 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.
LB  - PUB:(DE-HGF)16
C6  - pmid:29309116
UR  - <Go to ISI:>//WOS:000424728800052
DO  - DOI:10.1021/acsami.7b17142
UR  - https://juser.fz-juelich.de/record/867952
ER  -