A STUDY OF STRUCTURAL NON-STOICHIOMETRY WITH RESPECT TO OXYGEN IN RBaCo4O7+x SINGLE CRYSTALS
N. V. Podberezskaya1, V. Yu. Komarov1,2, M. Yu. Kameneva1, L. P. Kozeeva1, A. N. Lavrov1
1Nikolaev Institute of Inorganic Chemistry, Siberian Branch, Russian Academy of Sciences, Novosibirsk, Russia
2Novosibirsk National Research State University, Novosibirsk, Russia
Keywords: кобальтаты, монокристаллы, нестехиометрия по кислороду, структурный анализ, обработка рентгендифракционных данных, структурные модели, cobaltates, single crystals, oxygen non-stoichiometry, structural analysis, X-ray diffraction data processing, structural models
Abstract
Impurity-free R BaCo4O7+ x ( R = Y, Lu) crystals are grown and the evolution of their structure with varying oxygen concentration in the range 0 £ x £ 1.3 is studied. The structural features of the studied samples required to develop an extended strategy of the X-ray crystallographic experiment, which made it possible to obtain more accurate data on unit cell parameters and additional information on the features of superstructure modulation and diffuse scattering, along with the phase composition of crystalline samples. A crystal chemical analysis of the known structural models of R BaCo4O7+ x is performed and suggestions are made about possible structural changes occurring when the oxygen concentration increases up to the limit.
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