An intermittent transition to chaotic flow by crystal rotation during Czochralski growth

We report on the transition to time-dependent flow which occurs at a certain critical rotational frequency fc of the crystal. The time-dependence is characterized by bursts of temperature drops near the crystal-melt interface and an analysis shows that the transition is of type III intermittency. This transition to time dependence is of significance for Czochralski growth of doped crystals because fc is in a typical range for growth. It is suggested that the striation analysis of Czochralski crystals should be done using the intermittency concept.