Buoyancy and surface tension driven flows in float zone crystal growth with a strong axial magnetic field

Abstract

The buoyancy driven flow due to the temperature gradient in the melt of a float zone and the surface tension driven flow due to the non-uniform temperature distribution along the free surface of the zone are studied in the presence of a strong axial magnetic field. The non-cylindrical shape of the zone is found to have a profound effect on the melt motion. The results indicate that the regions near the free surface are controlled mainly by the thermocapillarity, while the inner region is dominated by the buoyancy driven flow. Some implications for the mass transport of dopants in the molten float zone are discussed.