Seminars

"Ice - a material with many facets"

Speaker

Dr Christoph Salzmann
University College London

Time and Place

Thursday, 6 October 2016 - 11:00pm
CSEC Seminar Room

Abstract 

Ice is a material of fundamental importance for a vast range of critical processes in geology, biology, chemistry, the atmospheric sciences and space research. From the structural perspective, several different categories of ice materials exist including hydrogen-ordered, hydrogen-disordered, stacking-disordered and amorphous ices. This talk will give an overview over recent work in all those areas while keeping an eye on the implications our research has on the various areas of scientific research for which ice is an important material. In particular, new results on the low-temperature dynamics of the amorphous ices will be presented and it will be discussed if there are really two different kinds of liquid water at low temperatures as it has been suggested. Furthermore, it will be shown how one of the ice phases can be removed selectively from the phase diagram by using an impurity that is incompatible with its local structure. The wider implications of this new finding for crystal engineering and the general influences of impurities on crystallisation will be discussed. Finally, the topic of stacking disorder in ice will be introduced. It will be shown how stacking disorder in ice can be quantified by using both total scattering techniques and spectroscopy. Furthermore, the effects of stacking disorder on the physical and chemical properties of ice will be discussed including the shapes of snowflakes.