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 CdCO 3 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.
Bibliographical noteFunding Information:
This research was supported by the Deutsche Forschungsgemeinschaft under project number KN 507/5-1 in the framework of the priority program: “Synthesis, ‘in situ’ characterization and quantum mechanical modelling of Earth Materials, oxides, carbides, and nitrides at extremely high pressures and temperatures”. The use of the beamline X17C was supported by COMPRES, the Consortium for Materials Properties Research in Earth Sciences under NSF Cooperative Agreement EAR 06-49658. Use of the National Synchrotron Light Source, Brookhaven National Laboratory, was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-98CH10886. The authors would like to thank C. Tarabrella, Q. Guo and J. Hu for help during the measurements. Y. Lee and D.H. Seoung thank the support from the BK21 program to the Institute of Earth, Atmosphere, and Astronomy at Yonsei University and the Global Research Lab Program of the Ministry of Education, Science and Technology (MEST) of the Korean Government. Bjoern Winkler is grateful for funding from the BMBF in the framework of the Geotechnologienprogramm 03G0717B.
All Science Journal Classification (ASJC) codes
- Mechanics of Materials
- Mechanical Engineering
- Metals and Alloys
- Materials Chemistry