Equation of state and anharmonicity of carbon dioxide phase I up to 12 GPa and 800 K
Year: 2010
Authors: Giordano VM., Datchi F., Gorelli F.A., Bini R.
Autors Affiliation: European Synchrotron Radiat Facil, F-38043 Grenoble, France; Univ Paris 06, IMPMC, F-75015 Paris, France; CNRS, IMPMC, F-75015 Paris, France; LENS, I-50019 Florence, Italy; UOS Roma, IPCF CNR, I-00185 Rome, Italy; Univ Florence, Dipartimento Chim, I-50019 Florence, Italy.
Abstract: We present an extended investigation of phase I of carbon dioxide by x-ray diffraction and spectroscopic techniques at simultaneous high pressure and high temperature, up to 12 GPa and 800 K. Based on the present and literature data, we show that a Mie-Gruneisen-Debye model reproduces within experimental uncertainties the equation of state of CO(2) over the entire range of stability of phase I. Using infrared and Raman spectroscopy, we have determined the frequencies of the zone-center lattice modes as a function of pressure and temperature. We have then extracted the volume and temperature dependencies of the optical lattice mode frequencies and their respective Gruneisen parameters. We find a large difference between the thermodynamic Gruneisen parameter obtained from the P-V-T data and those associated with the optical lattice modes. This suggests, within the quasiharmonic approximation, that acoustic modes have a dominant contribution to the anharmonicity of the system. (C) 2010 American Institute of Physics. [doi:10.1063/1.3495951]
Journal/Review: JOURNAL OF CHEMICAL PHYSICS
Volume: 133 (14) Pages from: 144501-1 to: 144501-9
More Information: This work was supported by the European Union under Contract No. RII3-CT2003-506350. We thank B. Canny and J. C. Chervin for their technical assistance. The authors acknowledge the European Synchrotron Radiation Facility for the provision of beam time allocated to proposals HS-3392 and HD-226.KeyWords: High-pressure; Solid Co2; High-temperature; Lattice; Raman; Compressibility; Spectroscopy; Calibration; Velocities; ConstantsDOI: 10.1063/1.3495951Citations: 24data from “WEB OF SCIENCE” (of Thomson Reuters) are update at: 2024-10-20References taken from IsiWeb of Knowledge: (subscribers only)