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High-pressure transformations of NbO2F

Carlson, Stefan LU ; Larsson, Ann Kristin and Rohrer, Franziska E. (2000) In Acta Crystallographica. Section B: Structural Science, Crystal Engineering and Materials 56(2). p.189-196
Abstract

The ReO3-type structure NbO2F, niobium dioxyfluoride, has been studied at high pressures using diamond anvil cells and synchrotron X-ray radiation. High-pressure powder diffraction measurements have been performed up to 40.1 GPa. A phase transition from the cubic (Pm3m) ambient pressure structure to a rhombohedral (R3c) structure at 0.47 GPa has been observed. Rietveld refinements at 1.38, 1.96, 3.20, 6.23, 9.00 and 10.5 GPa showed that the transition involves an a-a-a- tilting of the cation-anion coordination octahedra and a change of the anion-anion arrangement to approach hexagonal close packing. Compression and distortion of the Nb(O/F)6 octahedra is also revealed by... (More)

The ReO3-type structure NbO2F, niobium dioxyfluoride, has been studied at high pressures using diamond anvil cells and synchrotron X-ray radiation. High-pressure powder diffraction measurements have been performed up to 40.1 GPa. A phase transition from the cubic (Pm3m) ambient pressure structure to a rhombohedral (R3c) structure at 0.47 GPa has been observed. Rietveld refinements at 1.38, 1.96, 3.20, 6.23, 9.00 and 10.5 GPa showed that the transition involves an a-a-a- tilting of the cation-anion coordination octahedra and a change of the anion-anion arrangement to approach hexagonal close packing. Compression and distortion of the Nb(O/F)6 octahedra is also revealed by the Rietveld refinements. At 17-18 GPa, the diffraction pattern disappears and the structure becomes X-ray amorphous.

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author
organization
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type
Contribution to journal
publication status
published
in
Acta Crystallographica. Section B: Structural Science, Crystal Engineering and Materials
volume
56
issue
2
pages
8 pages
publisher
Wiley-Blackwell
external identifiers
  • Scopus:0001282393
ISSN
0108-7681
language
English
LU publication?
yes
id
d6cf7bf9-d9a0-430e-9047-c3f89854abe4
date added to LUP
2016-05-04 13:26:47
date last changed
2016-10-19 09:52:33
@misc{d6cf7bf9-d9a0-430e-9047-c3f89854abe4,
  abstract     = {<p>The ReO<sub>3</sub>-type structure NbO<sub>2</sub>F, niobium dioxyfluoride, has been studied at high pressures using diamond anvil cells and synchrotron X-ray radiation. High-pressure powder diffraction measurements have been performed up to 40.1 GPa. A phase transition from the cubic (Pm3m) ambient pressure structure to a rhombohedral (R3c) structure at 0.47 GPa has been observed. Rietveld refinements at 1.38, 1.96, 3.20, 6.23, 9.00 and 10.5 GPa showed that the transition involves an a<sup>-</sup>a<sup>-</sup>a<sup>-</sup> tilting of the cation-anion coordination octahedra and a change of the anion-anion arrangement to approach hexagonal close packing. Compression and distortion of the Nb(O/F)<sub>6</sub> octahedra is also revealed by the Rietveld refinements. At 17-18 GPa, the diffraction pattern disappears and the structure becomes X-ray amorphous.</p>},
  author       = {Carlson, Stefan and Larsson, Ann Kristin and Rohrer, Franziska E.},
  issn         = {0108-7681},
  language     = {eng},
  number       = {2},
  pages        = {189--196},
  publisher    = {ARRAY(0x83fa988)},
  series       = {	Acta Crystallographica. Section B: Structural Science, Crystal Engineering and Materials },
  title        = {High-pressure transformations of NbO<sub>2</sub>F},
  volume       = {56},
  year         = {2000},
}