On the nature of amorphous polymorphism of water

Michael Marek Koza; Burkhard Geil; Katrin Winkel; Christian Koehler; Franz Czeschka; Marco Scheuermann; Helmut Schober; Thomas Hansen

doi:10.1103/physrevlett.94.125506

arXiv · cond-mat/0506532

On the nature of amorphous polymorphism of water

Michael Marek Koza·Burkhard Geil·Katrin Winkel·Christian Koehler·Franz Czeschka·Marco Scheuermann·Helmut Schober·Thomas Hansen

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Abstract

We report elastic and inelastic neutron scattering experiments on different amorphous ice modifications. It is shown that an amorphous structure (HDA') indiscernible from the high-density phase (HDA), obtained by compression of crystalline ice, can be formed from the very high-density phase (vHDA) as an intermediate stage of the transition of vHDA into its low-density modification (LDA'). Both, HDA and HDA' exhibit comparable small angle scattering signals characterizing them as structures heterogeneous on a length scale of a few nano-meters. The homogeneous structures are the initial and final transition stages vHDA and LDA', respectively. Despite, their apparent structural identity on a local scale HDA and HDA' differ in their transition kinetics explored by in situ experiments. The activation energy of the vHDA-to-LDA' transition is at least 20 kJ/mol higher than the activation energy of the HDA-to-LDA transition.

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Michael Marek Koza, Burkhard Geil, Katrin Winkel, Christian Koehler, Franz Czeschka, Marco Scheuermann, Helmut Schober, Thomas Hansen. 2005-06-21. On the nature of amorphous polymorphism of water. https://doi.org/10.1103/physrevlett.94.125506

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