In-situ observation of temperature dependent microstructural changes in HPT-produced p-type skutterudites

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216224%3A14310%2F24%3A00135596" target="_blank" >RIV/00216224:14310/24:00135596 - isvavai.cz</a>

Výsledek na webu

<a href="https://www.sciencedirect.com/science/article/pii/S0925838824000173" target="_blank" >https://www.sciencedirect.com/science/article/pii/S0925838824000173</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.jallcom.2024.173431" target="_blank" >10.1016/j.jallcom.2024.173431</a>

Jazyk výsledku

angličtina

Název v původním jazyce

In-situ observation of temperature dependent microstructural changes in HPT-produced p-type skutterudites

Popis výsledku v původním jazyce

To build thermoelectric generators, leg materials with a high figure of merit, ZT, are essential. Skutterudites are promising candidates because besides being environmentally friendly, the starting material is available and cheap and they can be used in a wide temperature range. To enhance ZT, severe plastic deformation via high-pressure torsion, HPT, was successfully applied on ball-milled and hot-pressed skutterudites as well as to directly densify skutterudite powder. Severe plastic deformation introduces many defects, mainly dislocations, into the sample and in parallel the crystallite size is significantly reduced. During measurement-induced heating these defects anneal partially out, and the grains grow. It was observed that while heating HPT processed material from room temperature to about 850 K, changes of the temperature-dependent physical properties, most of all the electrical resistivity, the density, and the thermal expansion occur more or less simultaneously around 600 K. For the first time we have combined in situ TEM observations as well as in situ measurements of the elastic modulus and hardness in order to get a deeper insight into the microstructural behavior of a p-type skutterudite, DD0.7Fe3CoSb12 (DD = didymium) during increasing temperature from 300 K to 823 K. HPT-DD0.7Fe3CoSb12 is a high quality thermoelectric material with 1.2 &lt; ZT &lt; 1.4 at 750 K (hot-pressed reference sample: ZT ∼ 1.2 at 810 K).

Název v anglickém jazyce

In-situ observation of temperature dependent microstructural changes in HPT-produced p-type skutterudites

Popis výsledku anglicky

To build thermoelectric generators, leg materials with a high figure of merit, ZT, are essential. Skutterudites are promising candidates because besides being environmentally friendly, the starting material is available and cheap and they can be used in a wide temperature range. To enhance ZT, severe plastic deformation via high-pressure torsion, HPT, was successfully applied on ball-milled and hot-pressed skutterudites as well as to directly densify skutterudite powder. Severe plastic deformation introduces many defects, mainly dislocations, into the sample and in parallel the crystallite size is significantly reduced. During measurement-induced heating these defects anneal partially out, and the grains grow. It was observed that while heating HPT processed material from room temperature to about 850 K, changes of the temperature-dependent physical properties, most of all the electrical resistivity, the density, and the thermal expansion occur more or less simultaneously around 600 K. For the first time we have combined in situ TEM observations as well as in situ measurements of the elastic modulus and hardness in order to get a deeper insight into the microstructural behavior of a p-type skutterudite, DD0.7Fe3CoSb12 (DD = didymium) during increasing temperature from 300 K to 823 K. HPT-DD0.7Fe3CoSb12 is a high quality thermoelectric material with 1.2 &lt; ZT &lt; 1.4 at 750 K (hot-pressed reference sample: ZT ∼ 1.2 at 810 K).

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10403 - Physical chemistry

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2024

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Journal of Alloys and Compounds

ISSN

0925-8388

e-ISSN

1873-4669

Svazek periodika

977

Číslo periodika v rámci svazku

March 2024

Stát vydavatele periodika

CH - Švýcarská konfederace

Počet stran výsledku

8

Strana od-do

1-8

Kód UT WoS článku

001157988300001

EID výsledku v databázi Scopus

2-s2.0-85182028084