Low Temperature Physics: 26, 653 (2000); https://doi.org/10.1063/1.1312391 (8 pages)
Физика Низких Температур: Том 26, Выпуск 9-10 (Сентябрь 2000), c. 889-898    ( к оглавлению , назад )

Observation of the high resolution infrared absorption spectrum of CO2 molecules isolated in solid parahydrogen

Simon Tam and Mario E. Fajardo

Propulsion Directorate, U.S. Air Force Research Laboratory AFRL/PRSP, Bldg. 8451, Edwards AFB, CA 93524√7680
E-mail: mario_fajardo@ple.af.mil

Received February 17, 2000, revised May 4, 2000

Аннотация

We report the observation of high resolution (0.008 cm-1) infrared absorption spectra of CO2 molecules isolated in solid parahydrogen(pH2) matrices at T=2.4 to 4.8 K. Several extremely sharp (0.01 to 0.04 cm-1 full-width-at-half-maximum) absorption features appear in the 2343.5 to 2345 cm-1 region. We assign the three strongest peaks to the n3 mode of isolated CO2 molecules. The spectra are consistent with trapping of the CO2 molecules in three distinct double-substitutional sites in hcp and fcc regions of the pH2 solid. We offer several hypotheses as to the origins of the numerous weaker absorption features.

PACS:
07.20.Mc - Cryogenics; refrigerators, low-temperature detectors, and other low-temperature equipment
61.72.Ww - Doping and impurity implantation in other materials
67.80.-s - Solid helium and related quantum crystals
78.30.-j - Infrared and Raman spectra (for vibrational states in crystals and disordered systems, see 63.20.-e and 63.50.+x respectively)
81.10.Bk - Growth from vapor
81.30.Kf - Martensitic transformations