Improvements in the purification of cadmium telluride by zone refining

Abstract Several improvements have been made in the vertical zone refining technique used for the purification of cadmium telluride. The graphite susceptor used in RF heating is a split ring instead of the full ring used previously. Therefore, the molten zone is heated by direct RF coupling rather than by thermal radiation from the susceptor. An RF power of only 300–400 W is sufficient for refining cadmium telluride ingots of 25 mm diameter.