The role of lattice defects for structural, mechanical, and physical properties of HPT processed p-type skutterudite DD0.7Fe3CoSb12

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68081723%3A_____%2F25%3A00637112" target="_blank" >RIV/68081723:_____/25:00637112 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/00216224:14310/25:00141835

Výsledek na webu

<a href="https://www.sciencedirect.com/science/article/pii/S1359645425005774?via%3Dihub" target="_blank" >https://www.sciencedirect.com/science/article/pii/S1359645425005774?via%3Dihub</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.actamat.2025.121290" target="_blank" >10.1016/j.actamat.2025.121290</a>

Jazyk výsledku

angličtina

Název v původním jazyce

The role of lattice defects for structural, mechanical, and physical properties of HPT processed p-type skutterudite DD0.7Fe3CoSb12

Popis výsledku v původním jazyce

HPT (high pressure torsion)-processed samples of p-type skutterudite DD0.7Fe3CoSb12 were systematically ninvestigated for clarifying the mechanisms behind the enhancements of mechanical properties and particularly of nthe thermoelectric figure of merit ZT. For the first time we combined experiments (differential scanning calonrimetry, X-ray diffractometry, energy dispersive spectroscopy, and scanning electron microscopy) with calcunlations by density functional theory (DFT). The results demonstrated that the individual thermal stabilities of nlattice defects from HPT-processing with special respect to their densities and arrays are responsible for the nproperties observed. The mechanical properties are mainly governed by dislocations and grain boundaries, while nthe thermoelectric figure of merit ZT is affected by the generation and annihilation of vacancy type defects: These nallow for the formation of low-angle grain boundaries out of the HPT induced dislocations with increasing nmisorientation between the grains as a function of deformation and annealing temperature. In contrast to simply nentangled dislocation cell walls, these low/high angle grain boundaries account for a minimum of the product of nresistivity and thermal conductivity, and thus of a maximum of ZT. DFT calculations not only provided formation nenergies of vacancies for the three atom sites in NdFe4Sb12 and NdCo4Sb12, but also insight on the stabilities of nthese compounds. The Nd vacancy formation in NdCo4Sb12 is the least energy-demanding, which makes the nstructure more stable than e.g. the Nd vacancy formation in NdFe4Sb12, where decreasing electron deficit ncompetes with increasing structure distortion.

Název v anglickém jazyce

The role of lattice defects for structural, mechanical, and physical properties of HPT processed p-type skutterudite DD0.7Fe3CoSb12

Popis výsledku anglicky

HPT (high pressure torsion)-processed samples of p-type skutterudite DD0.7Fe3CoSb12 were systematically ninvestigated for clarifying the mechanisms behind the enhancements of mechanical properties and particularly of nthe thermoelectric figure of merit ZT. For the first time we combined experiments (differential scanning calonrimetry, X-ray diffractometry, energy dispersive spectroscopy, and scanning electron microscopy) with calcunlations by density functional theory (DFT). The results demonstrated that the individual thermal stabilities of nlattice defects from HPT-processing with special respect to their densities and arrays are responsible for the nproperties observed. The mechanical properties are mainly governed by dislocations and grain boundaries, while nthe thermoelectric figure of merit ZT is affected by the generation and annihilation of vacancy type defects: These nallow for the formation of low-angle grain boundaries out of the HPT induced dislocations with increasing nmisorientation between the grains as a function of deformation and annealing temperature. In contrast to simply nentangled dislocation cell walls, these low/high angle grain boundaries account for a minimum of the product of nresistivity and thermal conductivity, and thus of a maximum of ZT. DFT calculations not only provided formation nenergies of vacancies for the three atom sites in NdFe4Sb12 and NdCo4Sb12, but also insight on the stabilities of nthese compounds. The Nd vacancy formation in NdCo4Sb12 is the least energy-demanding, which makes the nstructure more stable than e.g. the Nd vacancy formation in NdFe4Sb12, where decreasing electron deficit ncompetes with increasing structure distortion.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10302 - Condensed matter physics (including formerly solid state physics, supercond.)

Projekt

<a href="/cs/project/LM2023039" target="_blank" >LM2023039: Centrum výzkumu a vývoje plazmatu a nanotechnologických povrchových úprav</a><br>

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2025

Kód důvěrnosti údajů

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

Název periodika

Acta Materialia

ISSN

1359-6454

e-ISSN

1873-2453

Svazek periodika

296

Číslo periodika v rámci svazku

SEP

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

12

Strana od-do

121290

Kód UT WoS článku

001524815700001

EID výsledku v databázi Scopus

2-s2.0-105009474292