High pressure polymorphism of ?-TaON
High pressure polymorphism of ?-TaON
The high pressure behavior of TaON was studied using a combination of Raman scattering, synchrotron X-ray diffraction, and X-ray absorption spectroscopy in diamond anvil cells to 70 GPa at ambient temperature. A Birch–Murnaghan equation of state fit for baddeleyite structured ?-TaON indicates a high bulk modulus value Ko = 328 ± 4 GPa with K?o = 4.3. EXAFS analysis of the high pressure XAS data provides additional information on changes in the Ta–(O,N) and Ta–Ta distances. Changes in the X-ray diffraction patterns and Raman spectra indicate onset of a pressure induced phase transition near 33 GPa. Our analysis indicates that the new phase has an orthorhombic cotunnite-type structure but that the phase transition may not be complete even by 70 GPa. Similar sluggish transformation kinetics are observed for the isostructural ZrO2 phase. Analysis of compressibility data for the new cotunnite-type TaON phase indicate a very high bulk modulus Ko 370 GPa, close to the theoretically predicted value.
9647-9654
Woodhead, K.
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Pascarelli, S.
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Hector, A.L.
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Briggs, R.
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Alderman, N.
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McMillan, P. F.
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7 July 2014
Woodhead, K.
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Pascarelli, S.
ce345fc4-e758-4c49-9da1-323ef3f06500
Hector, A.L.
f19a8f31-b37f-4474-b32a-b7cf05b9f0e5
Briggs, R.
6181bb2b-07eb-4850-aabc-d106f13a39b0
Alderman, N.
0bf3a57d-dc33-491d-b5fd-0922098edabf
McMillan, P. F.
4e58bad1-40b7-4a4b-81d2-461698be92b3
Woodhead, K., Pascarelli, S., Hector, A.L., Briggs, R., Alderman, N. and McMillan, P. F.
(2014)
High pressure polymorphism of ?-TaON.
Dalton Transactions, 43 (25), .
(doi:10.1039/c4dt00805g).
Abstract
The high pressure behavior of TaON was studied using a combination of Raman scattering, synchrotron X-ray diffraction, and X-ray absorption spectroscopy in diamond anvil cells to 70 GPa at ambient temperature. A Birch–Murnaghan equation of state fit for baddeleyite structured ?-TaON indicates a high bulk modulus value Ko = 328 ± 4 GPa with K?o = 4.3. EXAFS analysis of the high pressure XAS data provides additional information on changes in the Ta–(O,N) and Ta–Ta distances. Changes in the X-ray diffraction patterns and Raman spectra indicate onset of a pressure induced phase transition near 33 GPa. Our analysis indicates that the new phase has an orthorhombic cotunnite-type structure but that the phase transition may not be complete even by 70 GPa. Similar sluggish transformation kinetics are observed for the isostructural ZrO2 phase. Analysis of compressibility data for the new cotunnite-type TaON phase indicate a very high bulk modulus Ko 370 GPa, close to the theoretically predicted value.
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e-pub ahead of print date: 8 May 2014
Published date: 7 July 2014
Organisations:
Engineering Science Unit, Electrochemistry
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Local EPrints ID: 366639
URI: http://eprints.soton.ac.uk/id/eprint/366639
ISSN: 0300-9246
PURE UUID: edded490-eb87-49d2-a23b-b1690414842b
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Date deposited: 07 Jul 2014 09:05
Last modified: 15 Mar 2024 02:52
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Contributors
Author:
K. Woodhead
Author:
S. Pascarelli
Author:
R. Briggs
Author:
N. Alderman
Author:
P. F. McMillan
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