Temperature oscillations in molten metals and their relationship to growth striae in melt-grown crystals

Abstract

Experiments are reported which show that the temperature distribution in molten gallium contained in a horizontal boat on which is impressed an axial temperature gradient becomes oscillatory when the temperature gradient exceeds a critical value. It is proposed that the oscillations are an example of the phenomenon of “overstability” reported to occur in rotated Bénard cells. The oscillations probably produce impurity striations in meltgrown crystals; it is shown that the oscillations are suppressed by the application of a transverse magnetic field.