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Tantalate systems relating to alternative substrate materials for heteroepitaxial growth of GaN and LiNbO3 thin filmsтезисы доклада
- Авторы: Volkova E.A., Maltsev V.V., Leonyuk N.I.
- Сборник: Abstr. Book of The Intern. Conf. on Advanced Materials and Crystal Growth (ROCAM-2003)
- Тезисы
- Год издания: 2003
- Место издания: Constanta, Romania
- Аннотация: The complex systems Re2O3-Ta2O5-Li2B4O7, Re2O3-Ta2O5-K2B4O7, Re2O3-Ta2O5-KB5O8 and Re2O3-Ta2O5-K2Mo3O10-B2O3 are considered in light of the possibility of various structure formation in the field of existing melts. Phase formation was estimated through spontaneous nucleation after a long-time mixing of the overheated fluxed melts, mostly, near the lines corresponding to the initial molar ratios Nd2O3:Ta2O5 equal to 1:1, 1:3 and 1:7. As a result, the crystalline NdTa7O19, Nd0.33TaO3, Nd1.67Ta5O15, NdTaO4 and KTaO3 phases have been obtained. An increase in concentration of Nd2O3 in the complex melt leads to transformation in the coordinating number of Ta-polyhedrons as well as their polymerization. Step by step, isolated Ta tetrahedra in NdTaO4 with b-fergusonite type of structure are replaced by three-dimensional perovskite–like Nd0,33TaO3 containing tantalum-oxygen octahedra, and then by the framework with 3-, 4- and 5-fold rings in Nd1,67(TaO3)5. On the whole, decreasing Nd2O3/Ta2O5 ratio is accompanied by the increase in tantalum coordination numbers from 4 to 6 and even 7.
- Добавил в систему: Леонюк Николай Иванович