No abstract

A new method for determining the mechanisms and kinetics of atomic exchange across a liquid—solid interface during the freezing process is proposed and evaluated. The limitations of the method are entirely experimental, making the method effective only at freezing velocities less than 5×10—3 cm/sec.

The applicability of the ``thermal wave'' technique for determining the mechanism and kinetics of atomic exchange across the liquid—solid interface during melting and freezing has been tested for several different orientations of tin crystals. The experimental conditions produced low driving forces for melting and freezing. The results are consistent with atomic attachment at layer edges generated by screw dislocations. A ``diffuse interface'' model fits the kinetic data.