In Situ TEM Studies of Nanostructured Thermoelectric Materials: An Application to Mg-Doped Zn4Sb3 Alloy

Duc The Ngo; Le Thanh Hung; Ngo Van Nong

doi:10.1002/cphc.201700930

In Situ TEM Studies of Nanostructured Thermoelectric Materials: An Application to Mg-Doped Zn₄Sb₃ Alloy

Duc The Ngo^*, Le Thanh Hung, Ngo Van Nong

^*Corresponding author for this work

Technical University of Denmark

Research output: Contribution to journal › Article › peer-review

Abstract

We demonstrate an advanced approach using state of the art in situ transmission electron microscopy (TEM) to understand the interplay between nanostructures and thermoelectric (TE) properties of high-performance Mg-doped Zn₄Sb₃ TE systems. By using the technique, microstructure and crystal evolutions of TE material have been dynamically captured as a function of temperature from 300 K to 573 K. On heating, we have clearly observed precipitation and growth of a Zn-rich secondary phase as nanoinclusions in the matrix of primary Zn₄Sb₃ phase. Elemental mapping by STEM-EDX spectroscopy reveals enrichment of Zn in the secondary Zn₆Sb₅ nanoinclusions during the thermal processing without decomposition. Such nanostructures strongly enhances phonon scattering, resulting in a decrease in the thermal conductivity leading to a zT value of 1.4 at 718 K.

Original language	English
Pages (from-to)	108-115
Number of pages	8
Journal	ChemPhysChem
Volume	19
Issue number	1
Early online date	9 Oct 2017
DOIs	https://doi.org/10.1002/cphc.201700930
Publication status	Published - 5 Jan 2018

Keywords

electron diffraction
energy transfer
materials science
solid-state structures
Zn-Sb compounds

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10.1002/cphc.201700930

Cite this

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title = "In Situ TEM Studies of Nanostructured Thermoelectric Materials: An Application to Mg-Doped Zn4Sb3 Alloy",

abstract = "We demonstrate an advanced approach using state of the art in situ transmission electron microscopy (TEM) to understand the interplay between nanostructures and thermoelectric (TE) properties of high-performance Mg-doped Zn4Sb3 TE systems. By using the technique, microstructure and crystal evolutions of TE material have been dynamically captured as a function of temperature from 300 K to 573 K. On heating, we have clearly observed precipitation and growth of a Zn-rich secondary phase as nanoinclusions in the matrix of primary Zn4Sb3 phase. Elemental mapping by STEM-EDX spectroscopy reveals enrichment of Zn in the secondary Zn6Sb5 nanoinclusions during the thermal processing without decomposition. Such nanostructures strongly enhances phonon scattering, resulting in a decrease in the thermal conductivity leading to a zT value of 1.4 at 718 K.",

keywords = "electron diffraction, energy transfer, materials science, solid-state structures, Zn-Sb compounds",

author = "Ngo, {Duc The} and Hung, {Le Thanh} and {Van Nong}, Ngo",

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T2 - An Application to Mg-Doped Zn4Sb3 Alloy

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AB - We demonstrate an advanced approach using state of the art in situ transmission electron microscopy (TEM) to understand the interplay between nanostructures and thermoelectric (TE) properties of high-performance Mg-doped Zn4Sb3 TE systems. By using the technique, microstructure and crystal evolutions of TE material have been dynamically captured as a function of temperature from 300 K to 573 K. On heating, we have clearly observed precipitation and growth of a Zn-rich secondary phase as nanoinclusions in the matrix of primary Zn4Sb3 phase. Elemental mapping by STEM-EDX spectroscopy reveals enrichment of Zn in the secondary Zn6Sb5 nanoinclusions during the thermal processing without decomposition. Such nanostructures strongly enhances phonon scattering, resulting in a decrease in the thermal conductivity leading to a zT value of 1.4 at 718 K.

KW - electron diffraction

KW - energy transfer

KW - materials science

KW - solid-state structures

KW - Zn-Sb compounds

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DO - 10.1002/cphc.201700930

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