Another crystalline layer on crystal surface as a precursor of crystal-to-crystal transition

Ice surfaces have a thin layer of water below its melting temperature of 0 degrees Celsius. Such premelting phenomenon is important for skating and snowflake growth. Similarly, liquid often crystallizes into a thin layer of crystal on a flat substrate before reaching its freezing temperature, i.e. prefreezing. The thickness of the surface layer usually increases and diverges as approaching the phase transition (such as melting and freezing) temperature. Besides premelting and prefreezing, whether similar surface phenomenon exists as a precursor of a phase transition has rarely been explored. Scientists now propose that a polymorphic crystalline layer may form on a crystal surface before the crystal-crystal phase transition and names it pre-solid-solid transition.

from Top Technology News -- ScienceDaily https://ift.tt/80iBOwo