Argon collisions with amorphous water ice surfaces

• The dynamics of argon atom collisions with amorphous ice surfaces are investigated using molecular beam techniques and molecular dynamics simulations. The formation of an amorphous ice layer on top of crystalline ice at 110 K is shown to have a strong influence on Ar scattering. Compared to crystalline ice, trapping followed by desorption is favoured over inelastic scattering, and a strongly enhanced emission of argon in the backward direction is observed. Molecular dynamics simulation with different types of amorphous and crystalline surfaces are consistent with the experimental data and show that large scale corrugation is required to reproduce the experimental findings. It is concluded that argon scattering can be used to probe changes in surface structure on the nanometer length-scale, while it is relatively insensitive to changes on the molecular level, and it thereby complements other techniques for studies of structural changes of ice surfaces. (c) 2006 Elsevier B.V. All rights reserved.

Ämnesord

NATURVETENSKAP  -- Kemi -- Fysikalisk kemi (hsv//swe)

NATURAL SCIENCES  -- Chemical Sciences -- Physical Chemistry (hsv//eng)

Nyckelord

amorphous ice

argon

surface structure

molecular beam

molecular

dynamics

ELECTRON-STIMULATED DESORPTION

MOLECULAR-DYNAMICS SIMULATIONS

SOLID

WATER

ASTROPHYSICAL IMPLICATIONS

FILMS

MORPHOLOGY

DENSITY

CRYSTALLINE

ABSORPTION

KINETICS

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