Infrared study of high-pressure molecular phases of carbon dioxide

• Published in: Физика низких температур
• Date: 2006
• ISSN: 0132-6414
• Main Authors: Giordano, V.M., Gorelli, F.A., Bini, R.
• Format: Article
• Language: English
• Published: Фізико-технічний інститут низьких температур ім. Б.І. Вєркіна НАН України 2006
• Subjects: Cryocrystals
• Online Access: https://nasplib.isofts.kiev.ua/handle/123456789/120879
• Journal Title: Digital Library of Periodicals of National Academy of Sciences of Ukraine
• Cite this: Infrared study of high-pressure molecular phases of
 carbon dioxide / V.M. Giordano, F.A. Gorelli, R. Bini // Физика низких температур. — 2006. — Т. 32, № 11. — С. 1402–1408. — Бібліогр.: 24 назв. — англ.

The infrared absorption spectra of the high-pressure crystalline phases II, III and IV of solid
 CO₂ were studied by using a resistive heated diamond anvil cell up to 30 GPa. The employment of
 crystal slabs having thickness of ~ 2 m allowed the study of the strongly absorbing fundamental
 bending and antisymmetric stretching modes without saturation. These are the first data for phases
 II and IV in the fundamental modes spectral region, furthermore the high samples quality allowed
 to improve, with respect to previous studies, the characterization of the infrared spectra of phases I
 and III. The comparison of the spectral structure and of the frequency evolution with pressure of
 the crystal modes between phase I and the higher pressure phases clearly indicates the close
 resemblance among all these phases. In particular, the dramatic change of the intermolecular
 interaction claimed for phases II (dimeric association) and IV (large molecular bending) can be
 ruled out and, as a consequence, the hypothesis of a transition from the molecular phase I to the
 silica-like phase V through intermediate nonmolecular phases discarded.