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Preparation and characterization of metastable trigonal layered MSb2O6 phases (M = Co, Ni, Cu, Zn, Mg) and considerations on FeSb2O6статья
Статья опубликована в высокорейтинговом журнале
Информация о цитировании статьи получена из
Web of Science,
Scopus
Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 14 августа 2017 г.
- Авторы: Nikulin A.Yu, Zvereva E.A., Nalbandyan V.B., Shukaev I.L., Kurbakov A.I., Kuchugura M.D., Raganyan G.V., Popov Yu V., Ivanchenko V.D., Vasiliev A.N.
- Журнал: Dalton Transactions
- Том: 46
- Год издания: 2017
- Издательство: Royal Society of Chemistry
- Местоположение издательства: United Kingdom
- Первая страница: 6059
- Последняя страница: 6068
- DOI: 10.1039/C6DT04859E
- Аннотация: MSb2O6 compounds (M = Mg, Co, Ni, Cu, Zn) are known in the tetragonal trirutile forms, slightly distorted monoclinically with M=Cu due to the Jahn-Teller effect. In this work, using lowtemperature exchange reaction between ilmenite-type NaSbO3 and molten MSO4-KCl (or MgCl2-KCl) mixtures, these five compositions were prepared for the first time as trigonal layered rosiaite (PbSb2O6) type phases. On heating, they irreversibly transform to the known phases via amorphous intermediates, in contrast to previously studied isostructural MnSb2O6, where the stable phase is structurally related to the metastable one. Of course, the same method was found applicable for preparing stable rosiaite-type CdSb2O6. The formula volumes of the new phases show an excellent correlation with the ionic radii (except M=Cu for which a Jahn-Teller distortion is suspected) and are 2-3 % larger than those for the known forms, although all coordination numbers are the same. Crystal structure of CoSb2O6 has been refined by the Rietveld method: P 3 1m, a=5.1318(3) Å, c=4.5520(3) Å. Compounds with M = Co and Ni order antiferromagnetically at 11 and 15 K, respectively, but the copper compound does not show long-range magnetic order down to 1.5 K. A comparison between the magnetic behavior of metastable and stable polymorphs was carried out. FeSb2O6 could not be prepared because of the 2Fe2+ + Sb5+ = 2Fe3+ + Sb3+ redox reaction. This electron transfer creates an additional 5s2 shell for Sb and results in volume increase. Comparison of the formula volume for the stable mixture FeSbO4+0.5Sb2O4 with that extrapolated for FeSb2O6 predicts that the trirutile-type FeSb2O6 may be stabilized at high pressures.
- Добавил в систему: Васильев Александр Николаевич