Effects of a cusp magnetic field on the oscillatory convection coupled with crucible rotation in Czochralski crystal growth

Experimental results are presented of the oscillatory convection of mercury melts coupled with crucible rotation under an imposed cusp shaped magnetic field in a Czochralski crystal growing configuration. It is shown that irregular thermal waves induced by the crucible rotation can be transformed into regular waves by the action of cusp magnetic field. Consequently, temperature fluctuations underneath a fixed nonrotating disk as a crystal model are significantly suppressed. The suppression effect due to the cusp magnetic field is more efficient for lower depth-to-radius aspect ratios of melts in which the more regular wave occurs. (C) 1999 Elsevier Science B.V. All rights reserved.