at Google ScholarTitle data
Guevarra, Jonathan ; van Smaalen, Sander ; Rotiroti, Nicola ; Paulmann, Carsten ; Lichtenberg, Frank:
Crystal structure of Ca₅Nb₅O₁₇.
In: Journal of Solid State Chemistry.
Vol. 178
(2005)
Issue 9
.
- pp. 2934-2941.
ISSN 0022-4596
DOI: https://doi.org/10.1016/j.jssc.2005.07.007
Abstract in another language
The crystal structure of Ca 5 Nb 5 O 17 , an n = 5 member of the homologous series A n B n O 3 n + 2 , at room temperature has been determined by single-crystal X-ray diffraction using synchrotron radiation with a {CCD} area detector. The structure is monoclinic with spacegroup P 2 1 / c (b unique) and lattice parameters a = 7.7494 ( 3 ) Å, b = 5.4928 ( 1 ) Å, c = 32.241 ( 1 ) Å, and β = 96.809 ( 4 ) ∘ . It consists of perovskite-like slabs of corner-sharing NbO 6 octahedra separated by an interslab region, where the octahedra on opposite sides of the gap do not share oxygen atoms resulting in an extra layer of oxygen atoms with respect to the ideal perovskite structure. The slabs are five octahedra wide. Ca atoms within the slabs occupy 12-fold coordinated sites whereas those at the borders show irregular coordination environments. The distortion of the octahedra increases from the center to the borders of the slabs. The computed valences for the Nb ions are very close to 5 at the borders while smaller values were obtained for sites in the middle of the slabs which suggests that the electrical conduction takes place predominantly in the middle of the slabs.
Further data
| Item Type: | Article in a journal |
|---|---|
| Refereed: | Yes |
| Keywords: | Bond valence sum |
| Institutions of the University: | Faculties > Faculty of Mathematics, Physics und Computer Science > Group Material Sciences > Chair Crystallography > Chair Crystallography - Univ.-Prof. Dr. Sander van Smaalen Faculties Faculties > Faculty of Mathematics, Physics und Computer Science Faculties > Faculty of Mathematics, Physics und Computer Science > Group Material Sciences Faculties > Faculty of Mathematics, Physics und Computer Science > Group Material Sciences > Chair Crystallography |
| Result of work at the UBT: | Yes |
| DDC Subjects: | 500 Science > 530 Physics |
| Date Deposited: | 16 Mar 2016 09:04 |
| Last Modified: | 15 May 2024 11:48 |
| URI: | https://eref.uni-bayreuth.de/id/eprint/31837 |