Elementary growth processes and surface melting of ice crystals revealed by advanced optical microscopy

Abstract

Molecular-level understanding of ice crystal surfaces holds the key to unlocking the secrets of various fields. To observe ice crystal surfaces at the molecular level, we developed an advanced optical microscope, and succeeded in visualizing individual elementary steps of 0.37nm in height on ice basal faces. Utilizing this microscope, we also attempted to visualize the surface melting processes of ice crystals. We found the presence of two types of surface liquid phases (quasi-liquid layer phases)that exhibit different morphologies and dynamics on ice basal faces.