Origin of abnormally sharp features in collision-induced spectra of cryosolutions

Переведенное название: Природа аномально узких линий в индуцированных столкновениями спектрах криорастворов

W.A. Herrebout, B.J. Van Der Veken, A.P. Kouzov, N.N. Filippov

Результат исследований: Научные публикации в периодических изданияхстатья

1 Цитирования (Scopus)

Аннотация

A weak, paradoxically narrow resonance feature (shortly, ther-line) near the O2 fundamental frequency
in the collision-induced absorption spectrum of oxygen dissolved in liquid argon and liquid nitrogen
(T = 89 K) is resolved for the first time. An accurate band shape fitting routine to separate the r-line
from the by-far more intense diffuse background and to study its behavior versus the oxygen mole
fraction x which ranged from 0.03 up to 0.23 has been elaborated. At small x (.0.07), the r-line
intensity was found to scale as x2 leaving no doubt that it is due to the solute-solute (O2–O2) interactions.
In line with our results on the pH2–LNe cryosystem [Herrebout, Phys. Rev. Lett. 101, 093001 (2008)],
the Lorentzian r-line shape and its extraordinary sharpness (half width at half height ≈ 1 cm−1) are
indicative of the motional narrowing of the relative solute-solute translational spectrum. As x is further
raised, ternary solute-solute interactions impede the r-line growth in the O2–LAr spectrum because of
the cancellation effect [J. Van Kranendonk, Physica 23, 825 (1957)]. Theoretical arguments are given
that multiple interactions between the solutes should finally destroy the solute-solute induced r-line
when the mixed solution approaches the limit of the pure liquid (x = 1). Interestingly, the nonbinary
effects are too weak to appreciably affect the quadratic r-line scaling in the O2–LN2 cryosystem
which persists up to x = 0.23. It is emphasized that studies of the resonant features in the collisioninduced spectra of binary cryosolutions open up unique opportunities to spectroscopically trace the
microscopic-scale diffusion
Переведенное названиеПрирода аномально узких линий в индуцированных столкновениями спектрах криорастворов
Язык оригиналаанглийский
Номер статьи044508
Число страниц11
ЖурналJournal of Chemical Physics
Том143
Номер выпуска4
DOI
СостояниеОпубликовано - 2015

Предметные области Scopus

  • Физика и астрономия (все)

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