| Autor: |
V. N. Voronov, Alexander S. Krylov, Alexander Vtyurin, S. N. Krylova, S. V. Babushkin, T. B. Emelina, S. N. Sofronova, N. M. Laptash, S. V. Goryainov |
| Rok vydání: |
2011 |
| Předmět: |
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| Zdroj: |
Journal of Raman Spectroscopy. 43:577-582 |
| ISSN: |
0377-0486 |
| DOI: |
10.1002/jrs.3071 |
| Popis: |
Raman spectra of Rb2KTiOF5 crystal were obtained and analyzed in the temperature range from 77 to 297 K and under hydrostatic pressure up to 4.2 GPa (at T = 295 K). The experimental results were compared with quantum-chemical simulation of TiOF5 pseudo-octahedron. To interpret effects of lattice ordering, phonon spectra of several ordered phases of Rb2KTiOF5 were calculated within ab initio generalized Gordon–Kim model, and ordering of TiOF5 molecular groups were simulated within Monte Carlo approach. The spectra exhibited orientation disordering in the cubic phase under ambient conditions. Cooling below the phase transition temperature (215 K) leads to partial ordering of the structure. The isotropic perovskite-like phase was found to undergo first-order transition into a low-symmetry anisotropic phase at about 1 GPa. Further compression up to 4.1 GPa did not show any effects associated with phase transitions. Copyright © 2011 John Wiley & Sons, Ltd. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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