Structural and transport characteristics of substituted bismuth niobates

Abstract

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.

Crystal Structure and Characterization of La1-xBixMnO3+δ

“…The obtained precursors were annealed at 600°С and 1100°С (x=0.1-0.5) and 1200°С (x=0.0). Bismuth-containing electrolytes Bi 4 V 1.7 Fe 0.3 O 11 , Bi 13 Mo 5 O 34 and Bi 3 Nb 0.8 W 0.2 O 7.1 were synthesized using the solid-state method described elsewhere (1)(2)(3) to study their chemical compatibility with La 1-x Bi x MnO 3+δ electrodes. X-ray powder diffraction (XRD) patterns were collected using CuK α radiation on a D8 ADVANCE diffractometer equipped with a VÅNTEC position-sensitive detector and a β-filter, and on an Equinox 3000 Enel diffractometer.…”

“…Mn 3+ +Fe 2+ → Mn 2+ +Fe 3+ [ 2 ] Red-Ox titration was performed using automatic titrator (ATP -02, Akvilon, Russia) with 0.1 N K 2 Cr 2 O 7 solution as the titrant. The unreacted Fe 2+ ions from Mohr's salt after finishing reactions [1] and [2] was oxidized by Cr 2 O 7 2ions to get Fe 3+ according to the reaction [3]:…”

Defining "Giant" Electrostriction

“…Cubic bismuth oxide (Bi 2 O 3 ) in the δ phase adopts a defective fluorite structure with 25% of the oxygen sites left unoccupied [50][51][52] . It is one of the best solid-state ionic conductors (with a conductivity around 0.3 S/cm at 800 • C 53 ).…”

Crystal structure and conductivity of bismuth-containing complex oxides

“…The features of synthesis for each particular case are described in [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15].…”