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Linewidths and shifts of carbon dioxide CARS spectra near the critical point
Author(s) -
Arakcheev V. G.,
Bagratashvili V. N.,
Valeev A. A.,
Gordiyenko V. M.,
Kireev V. V.,
Morozov V. B.,
Olenin A. N.,
Popov V. K.,
Tunkin V. G.,
Yakovlev D. V.
Publication year - 2003
Publication title -
journal of raman spectroscopy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.748
H-Index - 110
eISSN - 1097-4555
pISSN - 0377-0486
DOI - 10.1002/jrs.1098
Subject(s) - laser linewidth , critical point (mathematics) , supercritical fluid , spectral line , chemistry , raman spectroscopy , carbon dioxide , analytical chemistry (journal) , condensed matter physics , thermodynamics , physics , optics , mathematical analysis , laser , mathematics , organic chemistry , chromatography , astronomy
Transformation of the Q‐branch in CARS spectra of the low‐wavenumber Fermi dyad 2ν 2 /ν 1 component was studied in CO 2 near the critical point ( T c = 31.03 °C, P c = 72.8 atm). CARS spectra were collected along several isotherms in the temperature and pressure ranges 25.6–36.1 °C and 48–118 atm, respectively. The dependence of linewidth on pressure has an extremum at temperatures >31 °C with a maximum linewidth ∼50% greater than in liquid CO 2 . The position of the maximum was shifted from the critical to higher pressure with temperature increase. Interpretation of this inhomogeneous broadening is given in terms of cluster microstructure of the supercritical fluid. Copyright © 2003 John Wiley & Sons, Ltd.