H 99 Influence of Oxygen Nonstoichiometry on the Special Properties of Solid Solutions LaNb2-2xTa2xVO9-delta (x = 0-0.4) and LaTa2-2xNb2xVO9-delta (x = 0-0.1) [] / M. G. Zuev, E. V. Arkhipova, L. A. Perelyaeva, L. V. Zolotukhina, O. B. Lapina, R. N. Pletnev // Journal of Solid State Chemistry. - 2002. - V.167, N 1. - С. 73-79 . - ISSN 0022-4596 Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): ТВЕРДЫЕ РАСТВОРЫ -- ОКСИДНАЯ НЕСТЕХИОМЕТРИЯ -- НЕСТЕХИОМЕТРИЯ ОКСИДНАЯ -- ЭПР -- ЭЛЕКТРОННЫЙ ПАРАМАГНИТНЫЙ РЕЗОНАНС -- ЯМР -- ЯДЕРНЫЙ МАГНИТНЫЙ РЕЗОНАНС -- ИК-СПЕКТРОСКОПИЯ -- ИНФРАКРАСНАЯ СПЕКТРОСКОПИЯ -- СПЕКТРОСКОПИЯ ИНФРАКРАСНАЯ -- СПЕКТРАЛЬНЫЕ СВОЙСТВА -- СВОЙСТВА СПЕКТРАЛЬНЫЕ -- La -- Nb -- Ta -- V -- ЛАНТАН -- НИОБИЙ -- ТАНТАЛ -- ВАНАДИЙ -- СПЕКТРОСКОПИЯ КОМБИНАЦИОННОГО РАССЕЯНИЯ Аннотация: Phase equilibria in the LaVO4-Nb2O5-Ta2O5 system were analyzed. New solid solutions LaTa2-2xNb2xVO9-delta (x = 0-0.1) and LaNb2-2xTa2xVO9-delta (x = 0-0.4) were detected in this system. The structures of the vanadate-niobate LaNb2VO9 and vanadate-tantalate LaTa2VO9 are not known. The structures of the vanadate-tantalate LaTa2VO9 and LaTa2VO9-based solid solutions are similar to the structure of LaTa7O19, which refers to the hexagonal crystal system. The influence of the oxygen nonstoichiometry delta (x) on crystallochemical characteristics and spectral properties of these solid solutions were examined by the X-ray phase analysis, IR and radio spectroscopic methods. A correlation between the nonstoichiometry delta (x) and the volume of a unit cell V(x) of solid solutions LaTa2-2xNb2xVO9-delta was found. The IR spectrum of LaTa2VO9-delta transformed in going from delta = 0 to delta # 0. Two types of VO4 tetrahedra were formed in solid solutions LaNb2-2xTa2xVO9-delta depending on delta (x) |