Defect structure and ionic conductivity in Bi3Nb0.8W0.2O7.1

The exchange interactions and the state of manganese atoms in the solid solutions in Bi3NbO7 of cubic and tetragonal modifications

“…Such a conclusion agrees with the assumption about clustering of niobiumoxygen octahedra advanced as the result of examining the superstructure in cubic and tetragonal bismuth niobate and in the solid solutions [3,8,9,[17][18][19][20][21]. The formation of dimers rather than more complex clusters or chains of paramagnetic atoms seems to be associated with a low concentration of paramagnetic atoms in the solid solutions under study.…”

“…Niobium atoms are located in distorted octahedra of oxygen atoms [9,14]. As a result of examining the crystal structure of bismuth niobate and its solid solutions by the methods of neutron and electron diffraction niobium atoms were found to be distributed in the lattice in a non-statistic manner [9,10,[14][15][16][17][18][19][20][21]. Niobium-oxygen octahedra are combined in chains and blocks via oxygen atoms.…”

“…Heterovalent substitution of 3d-element atoms, of Zr, Y, W, Er for niobium atoms results in an increase in conductivity [17][18][19][20][21]. The nature of the current carriers and the mechanism of conductivity of bismuth niobate are studied in [22,23].…”

Structural and transport characteristics of substituted bismuth niobates

“…For yttrium-free Bi 3 Nb 1 -y Zr y O 7 ± δ formulations, appear ance of the second phase at an increase in the concen tration of zirconium is observed at х = 0.4. Appearance of the second cubic phase is related by some authors [16,17] to structural rearrangements of oxygen ions within a cubic lattice. It is emphasized herewith that the chemical composition remains unchanged.…”

“…The data were refined for the Fm3m space group, in which the Bi, Y/Zr/Nb atoms occupy the 4a (0, 0, 0) sites, while oxygen occupies the 32f (0.3, 0.3, 0.3) and 48i (0.5, 0.2, 0.2) sites [17]. The results of specification do not contradict the above assumptions, but energy dispersive microanalysis was carried out to provide an accurate answer to the ques tion regarding the phase composition.…”