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La2Zr2O7/LaAlO3 Composite Prepared by Mixing Precipitated Precursors: Evolution of Its Structure under Sintering Full article

Journal Materials Chemistry and Physics
ISSN: 0254-0584 , E-ISSN: 1879-3312
Output data Year: 2020, Volume: 251, Article number : 123093, Pages count : 12 DOI: 10.1016/j.matchemphys.2020.123093
Tags Pyrochlore/perovskite composite; Coprecipitation and aging; TBCs
Authors Bespalko Yu 1,2 , Kuznetsova T. 1 , Kriger T. 1 , Chesalov Yu 1 , Lapina O. 1,2 , Ishchenko A. 1,2 , Larina T. 1 , Sadykov V. 1,2 , Stathopoulos V. 3
Affiliations
1 Boreskov Institute of Catalysis, Novosibirsk, Russia
2 Novosibirsk State University, Novosibirsk, Russia
3 National and Kapodistrian University of Athens

Funding (1)

1 Federal Agency for Scientific Organizations 0303-2016-0013

Abstract: For La2Zr2O7/LaAlO3 composite prepared by aging (100 °C/10 h) of the mixture of precipitated precursors of La-Zr-O and La-Al-O, evolution of its structural features after sintering in air in the range of 100–1300 °C was investigated by applying XRD, HRTEM, FTIR, Raman and UV–Vis spectroscopies, 27Al MAS NMR and 139La NMR. The initial composite forms a highly dispersed and disordered structure retaining considerable concentrations of residual anions (anions from the initial salts, water molecules and hydrogen bound hydroxyls) due to basic properties of La cations. Stepwise removal of these anions by calcinations results in the crystallization of La2(Al)O2CO3 at 500 °C with complete disordering of the system after heating at 700 °C. These transitions are accompanied by appearance of AlO4 polyhedra. The La-Zr-O- containing phase appeared for the first time at 900 °C as fluorite-like ZrO2 stabilized by La (Al) cations, and LaAlO3 (P2) phase is also observed along with admixtures of La2O3 and La10Al4O21. At 1100 °C fluorite-like ZrO2 converts into the La2Zr2O7 (P1) phase, and in the range of 1100–1300 °C mixed P1 and P2 oxides are the main phases. For P1 phase, structure becomes more ordered at higher sintering temperatures, while for P2 phase in composite the nanodomain structure is still observed in comparison with individual mixed oxide at 1300 °C. The molecular –scale features of domain boundaries in nanostructured La-Zr-O/La-Al-O composite as well as applied inexpensive method of its fabrication provide required bases for a broad practical application of this material for Thermal barrier coatings (TBCs).
Cite: Bespalko Y. , Kuznetsova T. , Kriger T. , Chesalov Y. , Lapina O. , Ishchenko A. , Larina T. , Sadykov V. , Stathopoulos V.
La2Zr2O7/LaAlO3 Composite Prepared by Mixing Precipitated Precursors: Evolution of Its Structure under Sintering
Materials Chemistry and Physics. 2020. V.251. 123093 :1-12. DOI: 10.1016/j.matchemphys.2020.123093 WOS Scopus РИНЦ ANCAN OpenAlex
Dates:
Submitted: Jul 31, 2019
Accepted: Apr 16, 2020
Published online: Apr 22, 2020
Published print: Sep 1, 2020
Identifiers:
Web of science: WOS:000549319900033
Scopus: 2-s2.0-85083731818
Elibrary: 43276992
Chemical Abstracts: 2020:825486
Chemical Abstracts (print): 173:251146
OpenAlex: W3017486939
Citing:
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Scopus 13
Web of science 13
Elibrary 13
OpenAlex 14
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