Evidence for negative cross correlations in vibrational dephasing in liquids: isotropic raman-line shift and width phenomena in isotopic mixtures of N2 and O2
To experimentally confirm the hypothesis of negative cross terms between different dephasing mechanisms, potentially leading to a broadening of the isotropic Raman line upon isotopic dilution, we present a detailed study on the concentration dependencies of all of the line shifts and widths in the four isotopic mixtures of type (15N14N)(x)-(14N2)(1-x), (15N2)(x)-(14N2)(1-x), (15N2)(x)-(15N14N)(1-x), and (16O2)(x)-(18O2)(1-x) near the normal boiling point of nitrogen at T = 77.35 K. A quite disparate behavior of the nitrogen oscillators compared to the oxygen oscillators was observed in respect to a change of their isotopic baths.
Keutel
D
Institut fur Physikalische Chemie, Friedrich-Schiller-Universitat Jena, D-07743 Jena, Germany.
Seifert
F
Oehme
KL
Asenbaum
A
Musso
M