On the oscillations in the solidification rate during facet growth under rotation

Abstract

Crystal growth from the melt with rotation of the crystal results in oscillations of the solidification rate in the regions of non-faceted growth. This phenomenon can be explained quantitatively by a simple geometrical evaluation. During facet growth the fluctuations have been found to be much smaller or zero by experiment. In the present work a calculation of these fluctuations using another geometrical model based on the dependence of the growth rate on the kinetic undercooling is attempted. This theoretical treatment verifies the smaller fluctuations in the regions of faceted growth; but it shows only a constant rate if the crystal axis coincides with the normal of the facet. The calculation shows a phase difference in the oscillations in the regions of faceted and non-faceted growth. By comparison of this theoretical work with experimental results it should be possible, to examine the usual assumptions on the mechanism of facet growth.