The effect of the underlying substrate on the crystallization kinetics of dense amorphous solid water films
- Pacific Northwest National Laboratory, Environmental Molecular Sciences Laboratory, 902 Battelle Boulevard, P.O. Box 999, MSN K8-88, Richland, Washington 99352 (United States)
The crystallization kinetics of thin, dense amorphous solid water films deposited on crystalline ice and Pt(111) substrates are investigated. A dramatic acceleration of the crystallization rate is observed for amorphous films on crystalline ice substrates. The acceleration originates from the absence of the nucleation process on the crystalline ice substrate which serves as a two-dimensional nucleus for the growth of the crystalline phase. This contrasts with the crystallization on a Pt(111) substrate which proceeds via bulk nucleation and three-dimensional growth. Activation energies for growth and nucleation are determined to be 56 and 140 kJ/mol, respectively, using the apparent activation energies measured on crystalline ice and Pt(111) substrates. For amorphous films deposited on crystalline ice substrates, the crystallization rate decreases rapidly with increasing distance from the crystalline ice substrate most probably due to crystallization-induced cracking of the films. (c) 2000 American Institute of Physics.
- OSTI ID:
- 20215718
- Journal Information:
- Journal of Chemical Physics, Vol. 112, Issue 13; Other Information: PBD: 1 Apr 2000; ISSN 0021-9606
- Country of Publication:
- United States
- Language:
- English
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