Effects of Temperature and Potassium Chloride impurity on the relative tilt grain boundary and surface free energies in ice

CARLOS LEONARDO DI PRINZIO; E. DRUETTA; NASELLO, OLGA BEATRIZ

hanover

Congreso; Physics and Chemistry of ice 2014; 2014

Dartmouth College

The grain boundary (GB) free energies relative to the surface free energies can be determined measuring the root angles of the GB grooves formed at the intersection of the GB with the free surface. The ice GB grooves were copied by plastic replicas and the topographic details were revealed with a Laser Confocal 3D Microscope. Values of were determined for high purity and potassium chloride doped ice bicrystals annealed at -5oC and -18oC. The studied sampled were tilt GB with between 100 and 1800. The used KCl concentrations were 1 and 10 mol/l and the conductivity of the pure ice was 0.3S. GB relative energies were also determined for tilt GB for different GB inclinations. The values for different tilt angles and GB inclinations and for different temperatures and impurity concentrations were analyzed and compared using the CSL (Coincidence Site Lattice) theory. For pure samples annealed at -18oC, it was found an important variation of with the grain boundary inclination. In general it was observed a remarkable correspondence between CSL planar density  and . Results showed that the increase of temperature and the impurity produce significant changes in the structure of GB and surface.