Controlling the melt temperature during zone refining and Czochralski crystal growth by sensing the viscous torque of the melt zone during operation

摘要

A method and apparatus for controlling a heated bath of molten material to obtain controlled solidification, wherein the molten bath is kept in constant rotational movement relative to the solid portion of the material being treated and the mechanical action due to the viscous friction which develops in the bath is detected and thereby controlled, said method being applicable to the floating zone method and the Czochralsky crystal drawing method and being capable of producing ingots of high dimensional regularity.