| Autor: |
Kameneva, M. Yu., Kozeeva, L. P., Lavrov, A. N., Komarov, V. Yu., Podberezskaya, N. V., Kuchumov, B. M., Rudina, N. A. |
| Předmět: |
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| Zdroj: |
Journal of Structural Chemistry; Jan2020, Vol. 61 Issue 1, p29-43, 15p |
| Abstrakt: |
The processes of phase formation in the Y-Ba-Co-O system doped with scandium are studied in the region of compositions 1:1:4:7. The mechanism of interaction of initial reagents changes with scandium concentration: at low scandium contents, the (Y1−yScy)BaCo4O7+x (R114) doped oxide is formed, similarly to the undoped system, through the YBaCo2O5+x (R112) phase; at significantly higher scandium contents (≥0.2), the role of the intermediate and the competing phase is played by BaCo1−yScyO3−x representing a number of solid solutions which are stable in wide ranges of temperatures and scandium contents. It is shown that scandium in the R114 structure preferably occupies the yttrium position (Y1−yScyBaCo4O7+x), and the maximum degree of substitution is ymax ≈ 0.3–0.35. When yttrium is substituted with a smaller (in terms of ionic radii) scandium atom, the size of the unit cell diminishes nearly isotropically, the maximum change of its volume being 2.0% (from 353.0 Å3 to 345.9 Å3). [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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