“High-pressure behavior of otavite (CdCO3)”
R. Minch, D. Seoung, L. Ehm, B. Winkler, K. Knorr, L. Peters, L.A. Borkowski, J.B. Parise, Y. Lee, L. Dubrovinsky, W. Depmeier
Journal of Alloys and Compounds
Vol.508, pp.251-257, 2010.10
The high-pressure, room temperature behavior of otavite (CdCO3) was investigated by angle-dispersive synchrotron radiation powder diffraction up to 40 GPa, Raman spectroscopy up to 23 GPa and quantum mechanical calculations based on density functional theory. The calcite-type structure of CdCO3 is stable up to at least ∼19 GPa as shown by Raman spectroscopy. The compression mechanism was obtained from structure refinements against the diffraction data. The quantum mechanical calculations propose a calcite–aragonite phase transition to occur at about 30 GPa. The existence of a pressure-induced phase transition is supported by the Raman and diffraction experiments. Evidence for the transformation is given by broadening of X-ray reflections and external Raman bands starting from about 19 GPa in both experiments.