States of H+-containing species and proton migration forms in hydrated niobates and tantalates of alkaline-earth metals with a perovskite-related structure / Animitsa I,Denisova T,Neiman A,Nepryahin A,Kochetova N,Zhuravlev N,Colomban P // SOLID STATE IONICS. - 2003. - V. 162, l. SI. - P. 73-81.

ISSN/EISSN:

0167-2738 / нет данных

Type:

Article; Proceedings Paper

Abstract:

Hydrated mobates and tantalates of alkaline-earth metals Sr6Ta2O11, Sr6Nb2O11, and Ba4Ca2Nb2O11 with a perovskiterelated structure have been investigated by using wide-line H-1 nuclear magnetic resonance (NMR), thermogravimetry (TG), conductivity measurements, and IR spectroscopy. TG investigations show that these phases can incorporate up to similar to1 mol of water, which corresponds to the theoretical limit of hydration. A vide-line H-1-NMR study indicates that the proton signal consists of three components, because protons were present in the form of (i) relatively isolated OH groups, (ii) paired OH groups bound with the same metal atom, and (iii) closely spaced OH groups belonging to different octahedra and localized within a defect cluster. The niobates and the tantalates have different ratios of those groups that may be explained by different coordination tendencies of niobium and tantalum and as a consequence a different arrangement of oxygen vacancies. A dehydration scheme may be proposed from a comparison analysis of the TG and H-1-NMR data for partially hydrated samples. (C) 2003 Elsevier B.V. All rights reserved.

Author keywords:

oxygen deficient cryolites; wide-line H-1-NMR; conductivity; water uptake; proton transport WATER; OXYGEN

DOI:

10.1016/S0167-2738(03)00248-0

Web of Science ID:

ISI:000186197100012

Соавторы в МНС:

Другие поля

Поле	Значение
Note	11th International Conference on Solid State Protonic Conductors (SSPC 11), UNIV SURREY, GUILDFORD, ENGLAND, AUG 27-30, 2002
Publisher	ELSEVIER SCIENCE BV
Address	PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS
Language	English
Keywords-Plus	WATER; OXYGEN
Research-Areas	Chemistry; Physics
Web-of-Science-Categories	Chemistry, Physical; Physics, Condensed Matter
Number-of-Cited-References	12
Usage-Count-Since-2013	7
Journal-ISO	Solid State Ion.
Doc-Delivery-Number	736WX