Boytsova, O., Dovgaliuk, I., Chernyshov, D., Eliseev, A., O'brien, P., Sutherland, A. J. and Bosak, A. (2019). Polar and non-polar structures of NH4TiOF3. Journal of Applied Crystallography, 52 (1), pp. 23-26.
Abstract
Ammonium oxofluorotitanate, NH4TiOF3, is probably the best known precursor for the synthesis of anatase mesocrystals. Transformation of NH4TiOF3 into TiO2 through thermal decomposition, accompanied by hydrolysis, preserves some structural features of the precursor. Currently, any discussion of the mechanism of this transformation is difficult, as the exact crystal structure of the starting compound is not available and no intermediate structures are known. This article describes the outcome of single-crystal and powder X-ray diffraction studies, revealing the existence of two polymorphs of the parent NH4TiOF3 at different temperatures. A second-order phase transition from the polar Pca21 α phase (1), stable at room temperature, to the Pma2 β phase (2) above ∼433 K has been demonstrated. The direction of the pseudo-fourfold axis in NH4TiOF3 coincides with the orientation of the fourfold axis of anatase mesocrystals, consistent with a topotactical transformation.
Publication DOI: | https://doi.org/10.1107/S1600576718016606 |
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Divisions: | Engineering & Applied Sciences Engineering & Applied Sciences > Chemical Engineering & Applied Chemistry Engineering & Applied Sciences > Aston Institute of Materials Research (AIMR) |
Additional Information: | ©2019 International Union of Crystallography. Boytsova, O., Dovgaliuk, I., Chernyshov, D., Eliseev, A., O'Brien, P., Sutherland, A. J. & Bosak, A. (2019). J. Appl. Cryst. 52. |
Uncontrolled Keywords: | Crystal and powder X-ray diffraction,NH TiOF,Second-order phase transition,Biochemistry, Genetics and Molecular Biology(all) |
Full Text Link: | |
Related URLs: |
http://scripts. ... 600576718016606
(Publisher URL) http://www.scop ... tnerID=8YFLogxK (Scopus URL) |
PURE Output Type: | Article |
Published Date: | 2019-01-01 |
Accepted Date: | 2018-11-21 |
Authors: |
Boytsova, O.
Dovgaliuk, I. Chernyshov, D. Eliseev, A. O'brien, P. Sutherland, A. J. ( ![]() Bosak, A. |