Substrate induced crystallization of amorphous solid water at low temperatures

Abstract

We show that N 2 monolayerdesorption from icesurfaces is a quantitative, highly sensitive method for following the surfacecrystallization kinetics at low temperatures. Vapor deposited water films on a crystalline ice substrate exhibit amorphous growth at temperatures below ∼110 K. The rate of crystallization for these amorphous films is dramatically accelerated compared to the rate of crystallization observed for the amorphous filmsdeposited directly on Pt(111). We find that the crystalline ice substrate acts as a two-dimensional nucleus for the growth of the crystalline phase, thereby accelerating the crystallization kinetics.