Abstract-The results of studying solid solutions with the composition of Bi 3 Nb 1 -y Zr y O 7 ± δ , Bi 2.95 Y 0.05 Nb 1 -y Zr y O 7 ± δ (y = 0-0.5; Δy = 0.1), and Bi 6.95 Y 0.05 Nb 2 -y Zr y O 15.5 (y = 0.1-1; Δy = 0.1) are pre sented. XRD and electron microscopy with X ray microanalysis are used to determine the homogeneity regions of solid solutions; crystallochemical parameters are calculated. It is shown that irrespective of the ratio of Bi : Nb, two cubic phases are formed at an increase in the dopant amount. One of these represents a solid solution based on Bi 3 NbO 7 (δ phase) and the second one is a solid solution based on δ Bi 2 O 3 (δ' phase). Conductivity of sintered samples is studied using the impedance spectroscopy technique. Introduction of yttrium into the bismuth sublattice results in no increase in conductivity of solid solutions, while in the case of the ratio of Bi : Nb = 3 : 1, overall conductivity of solid solutions is somewhat higher at similar dopant con centrations.
In the paper, a comprehensive systematic study of different classes of bismuth containing oxide compounds was carried out. The relationship between composition, temperature and concentration regions of existence of stable, specific structure and properties of solid solutions on the basis of vanadates, molybdates, niobates and bismuth was found. The general regularities of synthesis of solid solutions with different variants of solid-phase and soluble methods were determined. On this basis, the optimal conditions for obtaining single-phase materials were formulated. For the first time the temperature and concentration boundaries of the regions of homogeneity and areas of stable existence of polymorphic modifications of solid solutions were defined and/or refined. The structural parameters of the synthesized phases were determined. By the method of electrochemical impedance spectroscopy the nature and features of impedance spectra, the temperature and concentration dependences of electrical conductivity of ceramic materials based on bismuth containing complex oxides were identified.
Doped lanthanum manganites La 1-x Bi x Mn 1-y Fe y O 3-δ (x=0.0-0.3; у=0.0-0.5, Δх, у=0.1) with perovskite-like structure were synthesized by solid state reaction and solution method. It was determined by X-ray diffraction that sintered samples have rhombohedral symmetry (S.G. R-3c). The parameters of unit cell were calculated. The morphology of briket was investigated by scanning electron microscopy. It was found that sintered sample is homogeneous, porous and grains are formed by different size. Elemental composition was checked by atomic emission spectroscopy. Additional studies were performed by TG/DSC and laser diffraction (analysis of particle size distribution).
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