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Interplay between Fe(II) and Fe(III) and Its Impact on Thermoelectric Properties of Iron-Substituted Colusites Cu26-xFexV2Sn6S32статья
- Авторы: Polevik Alexey O., Sobolev Alexey V., Glazkova Iana S., Presniakov Igor A., Verchenko Valeriy Yu, Link Joosep, Stern Raivo, Shevelkov Andrei V.
- Журнал: Compounds
- Том: 3
- Номер: 2
- Год издания: 2023
- Издательство: MDPI
- Местоположение издательства: Basel, Switzerland
- Первая страница: 348
- Последняя страница: 364
- DOI: 10.3390/compounds3020027
- Аннотация: Following the trend of finding better thermoelectric materials among synthetic analogs of copper–chalcogenide minerals, we have synthesized iron-bearing colusites of a general formula Cu26−xFexV2Sn6S32. They crystallize in the cubic space group P-43n with the unit cell parameter increasing linearly with the iron content. At a low iron concentration, the crystal structure features disorder manifested by an anti-site effect and a shift of a part of the tin atoms from their ideal positions, which is absent for higher iron contents. The magnetization and 57Fe/119Sn Mössbauer studies showed that, for x = 1, iron is present as Fe3+, whereas for x > 1, Fe2+ and Fe3+ coexist. Additionally, weak antiferromagnetic interactions between iron atoms and fast on the 57Fe Mössbauer time scale (107–109 s−1) electron transfer between adjacent Fe2+ and Fe3+ centers were revealed. Thermoelectric studies showed that iron-bearing colusites are p-type semiconductors with low thermal conductivity stemming from their complex crystal structure and structural disorder. The highest ZT of 0.78 at 700 K was found for the x = 1 iron content, where iron is present as Fe3+ only.
- Добавил в систему: Полевик Алексей Олегович