The nature and the mechanism of ion transfer in tungstates Me2+\{WO4\} (Ca, Sr, Ba) and Me (2) (3+) \{WO4\}(3) (Al, Sc, In) according to the data acquired by the tubandt method / Neiman A. Ya.,Pestereva N. N.,Zhou Y.,Nechaev D. O.,Koteneva E. A.,Vanec K.,Higgins B.,Volkova N. A.,Korchuganova I. G. // RUSSIAN JOURNAL OF ELECTROCHEMISTRY. - 2013. - V. 49, l. 9. - P. 895-907.

ISSN/EISSN:

1023-1935 / нет данных

Type:

Article

Abstract:

The Tubandt method of electrolysis is used for studying the nature of ionic carriers in ceramics of tungstates Me2+\{WO4\} (Ca, Sr, Ba) and Me (2) (3+) \{WO4\}(3) (Al, Sc, In) which are solid electrolytes. These compounds have the salt-like islet structure with isolated tetrahedrons \{WO (4) (2-) \} and are crystallized in the allied structural types of scheelite (CaWO4) for Me2+ and Sc tungstate (Sc-2\{WO4\}(3)) for Me3+. The electrolysis is carried out in 2- or 3-section cells (-)Pt|M (2) (n/n+) \{WO4\}|Me (2) (n/n+) \{WO4\}|Pt(+) in air atmosphere at the temperature of similar to 900A degrees C and cell voltage of 4 and 300 V. All experiments without exception demonstrate a decrease in the mass of the cathodic section of cells. This points to the negative charge of ionic mass carriers and their transfer towards the Pt(+) electrode. The cathodic briquette mass loss Delta m ((-)) depends linearly on the charge passed through a cell. In all experiments with MeWO4 tungstates, the anodic disk mass remains constant. The electrolysis of Me-2(WO4)(3) cells is always accompanied by an increase in the anolyte mass Delta m ((+)); however, in all experiments, Delta m ((-)) > Delta m ((+)). All data on mass variation and the results of studying the composition of nearelectrode electrolyte layers by XRD and SEM methods correspond to the condition (C is the cation), i.e., \{WO (4) (2-) \} anions pertain to the major ionic carriers. The transport number is calculated based on the Faraday law from Delta m ((-)). It is shown that the second ionic carrier with the mobility even higher than that of \{WO (4) (2-) \} is the O2- ion. For middle values of transport numbers, their ratio is shown to be (0.5-0.8) > (0.2-0.5). No results that would confirm the involvement of Me2+ and Me3+ ions in conduction are obtained.

Author keywords:

tungstates with the scheelite and Sc-2(WO4)(3) structures; co-anion conduction type; determination of transport numbers for WO42- anions by the Tubandt method; catholyte mass loss; electrolysis produc TRANSPORT NUMBERS; BOND-LENGTH; DIFFUSION; CONDUCTION; CRYSTALS; OXIDES

DOI:

10.1134/S1023193512120075

Web of Science ID:

ISI:000325251500009

Соавторы в МНС:

Другие поля

Поле	Значение
Month	SEP
Publisher	MAIK NAUKA/INTERPERIODICA/SPRINGER
Address	233 SPRING ST, NEW YORK, NY 10013-1578 USA
Language	English
Keywords-Plus	TRANSPORT NUMBERS; BOND-LENGTH; DIFFUSION; CONDUCTION; CRYSTALS; OXIDES
Research-Areas	Electrochemistry
Web-of-Science-Categories	Electrochemistry
Author-Email	arkady.neiman@usu.ru
Funding-Acknowledgement	Ministry of Education and Science of the Russian Federation {[}5166]; Russian Foundation for Basic Research {[}06-03-90170-NNF\_a, 08-03-00144-a, 11-03-01209-a]; Ural Federal University {[}06-03-90170-NNF\_a]
Funding-Text	This study was carried out with the financial support from the Ministry of Education and Science of the Russian Federation (Analytical Departmental Program ``Development of the Scientific Potential of Higher School for 2009-2013{''
Number-of-Cited-References	37
Usage-Count-Last-180-days	3
Usage-Count-Since-2013	23
Journal-ISO	Russ. J. Electrochem.
Doc-Delivery-Number	229GZ