Morphology diagram of nonequilibrium patterns of ice crystals growing in supercooled water

The morphology diagram of ice crystal patterns, which grow freely in a supercooled water is obtained experimentally in a supercooling-tip velocity phase space. This diagram classifies eight nonequilibrium macroscopic structures growing in the supercooling temperature region of heterogeneous nucleation of ice in pure water at atmospheric pressure. We found different kinds of morphology transitions between structures such as the first order, Continuous, and the fork-like bifurcation transitions. It was shown that the nonequilibrium patterns exhibit various growing behaviours such as tip-splitting, tip-oscillating, and tip-stable modes. Supercoolings as large as 30degreesC can be achieved allowing ready access to both the diffusive and kinetic growth regimes. We found the supercooling ranges that correspond to kinetic regime of solidification in which tinder controlled conditions, for a given supercooling levels both fractal and nonfractal nonequilibrium growth patterns are reproducibly observed. The possible reasons for the competition between fractal and nonfractal structures growing in highly supercooled water are discussed. (C) 2002 Elsevier Science B.V. All rights reserved.