Crystal Structure of the Compound Bi2Zn2/3Nb4/3O7
- 1 June 2002
- journal article
- Published by Springer Nature in Journal of Materials Research
- Vol. 17 (6) , 1406-1411
- https://doi.org/10.1557/jmr.2002.0209
Abstract
The crystal structure of Bi2Zn2/3Nb4/3O7 was determined using a combination of electron, x-ray, and neutron powder diffraction. The compound crystallizes with a monoclinic zirconolite-like structure [C2/c (No.15) space group, a = 13.1037(9) Å, b = 7.6735(3) Å, c = 12.1584(6) Å, β = 101.318(5)°]. According to structural refinement using neutron diffraction data, Nb preferentially occupies six-fold coordinated sites in octahedral sheets parallel to the (001) planes, while Zn is statistically distributed between two half-occupied (5 + 1)-fold coordinated sites near the centers of six-membered rings of [Nb(Zn)O6] octahedra. The Nb/Zn cation layers alternate along the c-axis with Bi-layers, in which Bi cations occupy both eight- and seven-fold coordinated sites. The eight-fold coordinated Bi atoms exhibited strongly anisotropic thermal displacements with an abnormally large component directed approximately along the c-axis (normal to the octahedral layers).Keywords
This publication has 12 references indexed in Scilit:
- Bismuth zinc niobate pyrochlore dielectric thin films for capacitive applicationsJournal of Applied Physics, 2001
- Crystal Chemistry and Dielectric Properties of Chemically Substituted (Bi1.5Zn1.0Nb1.5)O7 and Bi2(Zn2/3Nb4/3)O7 PyrochloresJournal of the American Ceramic Society, 2000
- Structures, Phase Transformations, and Dielectric Properties of Pyrochlores Containing BismuthJournal of the American Ceramic Society, 1997
- Crystal chemistry, thermal expansion and dielectric properties of (Bi1.5Zn0.5)(Sb1.5Zn0.5)O7 pyrochloreMaterials Research Bulletin, 1997
- The use of element ratios to eliminate analytical bias in cold neutron prompt gamma-ray activation analysisJournal of Radioanalytical and Nuclear Chemistry, 1995
- Prompt-gamma activation analysisJournal of Research of the National Institute of Standards and Technology, 1993
- Low-Fire Bismuth-Based Dielectric Ceramics for Microwave UseJapanese Journal of Applied Physics, 1992
- Bond-valence parameters obtained from a systematic analysis of the Inorganic Crystal Structure DatabaseActa crystallographica Section B, Structural science, crystal engineering and materials, 1985
- Zirconolite, CaZr
x
Ti3−x
O7; structure refinements for near-end-member compositions with x = 0.85 and 1.30Acta Crystallographica Section B: Structural Science, Crystal Engineering and Materials, 1981
- Revised effective ionic radii and systematic studies of interatomic distances in halides and chalcogenidesActa Crystallographica Section A, 1976