The effect of an external magnetic field on natural convection during the crystal growth process from a melt.

Abstract

The effect of an external magnetic field on the natural convention of a melt, which is electrically conductive, has been studied in relation to the process of crystal growth. It is known that the convective flow of a melt seriously affects the quality of the crystal, and that the application of a magnetic field could be one of the most promising procedures. Both the Bridgman and the Czochralski growth processes have been modeled under the assumption that the external magnetic field is imposed vertically. The result of a numerical analysis has revealed that there is a minimum intensity of the magnetic field that is necessary to suppress the convective motion of the liquid, and that above this threshold intensity the flow velocity decreases as inversely proportional to the magnetic field squared.