Protons in Sr-3(Sr1+xNb2-x)O9-3x/2 perovskite / Glockner R,Neiman A,Larring Y,Norby T // SOLID STATE IONICS. - 1999. - V. 125, l. 1-4. - P. 369-376.

ISSN/EISSN:

0167-2738 / нет данных

Type:

Article; Proceedings Paper

Abstract:

The defect structure and transport properties of complex perovskites with the general formula Sr-3(Sr1+xNb2-x)O9-3x/2 have been studied through the use of thermogravimetry (TG), ac-conductivity and transport number measurements, comprising samples in the compositional range between Sr-3(SrNb2)O-9 (x = 0) and Sr-3(Sr1.5Nb1.5)O-8.25 (x = 1/2) (Sr/Nb ratio varying from 2 to 3). TG was used to measure the uptake of water, and the highest reversible water uptake was found for the end member Sr-3(Sr1.5Nb1.5)O-8.25 (x = 1/2). The total conductivity (as a function of pH(2)O, pO(2) and T) for a sample of composition Sr-3(Sr1.4Nb1.6)O-8.4 was fitted to a model based on Sr-acceptor defects compensated by doubly charged oxygen vacancies and protons. The partial conductivities found by transport number measurements support the modelled results. Oxygen ion conductivity dominates at high temperatures and protonic conductivity dominates below similar to 550 degrees C at ambient humidities. The enthalpy and entropy for the reaction of water with oxygen vacancies to form protons were found to be -160+/-5 kJ mol(-1) and -166+/-5 J K-1 mol(-1), respectively, for this sample. Oxygen ion and proton conductivities were also found to increase with Sr content. Moreover, the increase far exceeds the expected behaviour, and possible causes for this are discussed. (C) 1999 Elsevier Science B.V, All rights reserved.

Author keywords:

complex perovskite; oxygen ion conductivity; proton conductivity; enthalpy and entropy of hydration WATER-VAPOR

DOI:

10.1016/S0167-2738(99)00197-6

Web of Science ID:

ISI:000083122700045

Соавторы в МНС:

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Другие поля

Поле	Значение
Month	OCT
Note	9th International Conference on Solid State Protonic Conductors (SSPC-9), BLED, SLOVENIA, AUG 17-21, 1998
Organization	Univ Ljubljana, Stefan Inst, Dept Phys; Minist Sci \& Technol
Publisher	ELSEVIER SCIENCE BV
Address	PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS
Language	English
Keywords-Plus	WATER-VAPOR
Research-Areas	Chemistry; Physics
Web-of-Science-Categories	Chemistry, Physical; Physics, Condensed Matter
ORCID-Numbers	Larring, Yngve/0000-0002-6600-9951 Norby, Truls/0000-0003-0909-0439
Number-of-Cited-References	10
Usage-Count-Since-2013	10
Journal-ISO	Solid State Ion.
Doc-Delivery-Number	245RV