Synthesis and Properties of Nanocomposites with Mixed Ionic–Electronic Conductivity on the Basis
of Oxide Phases with Perovskite and Fluorite Structures
Full article
| Общее |
Language:
Английский,
Genre:
Full article,
Status:
Published,
Source type:
Translated
|
| Conference |
Structural Chemistry of Partially Ordered Systems, Nanoparticles and Nanocomposites: Topical Meeting of the European Ceramic Society
27-29 Jun 2006
,
Saint-Petersburg
|
| Journal |
Glass Physics and Chemistry
ISSN: 1087-6596
, E-ISSN: 1608-313X
|
| Output data |
Year: 2007,
Volume: 33,
Number: 4,
Pages: 320-334
Pages count
: 15
DOI:
10.1134/S1087659607040049
|
| Authors |
Sadykov V.A.
1,2
,
Borchert Yu.V.
2
,
Alikina G.M.
1
,
Lukashevich A.I.
1
,
Mezentseva N.V.
1
,
Muzykantov V.S.
1
,
Moroz E.M.
1
,
Rogov V.A.
1
,
Zaikovskii V.I.
1
,
Zyuzin D.A.
1
,
Uvarov N.F.
3
,
Ishchenko A.V.
1
,
Zy'ryanov V.V.
3
,
Smirnova A.
4
|
| Affiliations |
| 1 |
Boreskov Institute of Catalysis, Siberian Division, Russian Academy of Sciences, pr. Akademika Lavrent’eva 5, Novosibirsk, 630090 Russia
|
| 2 |
Novosibirsk State University, ul. Pirogova 2, Novosibirsk, 630090 Russia
|
| 3 |
Institute of Solid-State Chemistry and Mechanochemistry, Siberian Division, Russian Academy of Sciences,ul. Kutateladze 18, Novosibirsk, 630158 Russia
|
| 4 |
Connecticut Global Fuel Cell Center, University of Connecticut, 44 Weaver Rd., Storrs, CT, 06269-5233 United States
|
|
Funding (3)
|
1
|
Президиум СО РАН
|
95
|
|
2
|
North Atlantic Treaty Organization
|
SfP-980878
|
|
3
|
International Science and Technology Center
|
3234
|
Nanocomposites consisting of phases with fluorite (doped CeO2) and perovskite (LaMnO3, GdMnO3) structures are synthesized using the method of ester polymeric precursors (the Pechini method) and two sources of rare-earth elements (Ln), such as pure cerium and gadolinium salts or a commercial mixture of rare-earth carbonates containing La, Ce, Pr, Nd, and Sm cations. The genesis of the nanocomposite structure as a function of the sintering temperature is investigated using X-ray diffraction and electron microscopy. It is revealed that the genesis of the nanocomposite structure is governed, in many respects, by the fact that the decomposition of the ester polymeric precursor leads to the formation of a metastable phase, namely, a fluoritelike solid solution based on ceria with an excess concentration of the cations Ln3+ (Ln3+ = La3+, Pr3+, Nd3+, Sm3+) as compared to the equilibrium concentration. As a result, the perovskite phase (identified by X-ray diffraction analysis) is formed only after the subsequent annealing at temperatures higher than 800°C, when Ln3+ cations escape from particles of the solid solution. It is demonstrated that, at annealing temperatures of up to 1100°C, particles of both phases have nanometer sizes and are characterized by a uniform spatial distribution necessary for percolation. The nanocomposites possess a high total electrical conductivity and a high mobility of lattice oxygen. The reduction rate of the nanocomposites with hydrogen or methane is higher than the reduction rate of the individual phases. The characteristics of the nanocomposites prepared from the commercial mixture of rare-earth carbonates are better than those of the samples synthesized from the pure salts.