The Role of Evaporation in Zone Refining Indium Antimonide†

Experiments on the refining of InSb are described ; they include work with material heavily doped with zinc, cadmium, tellurium, and arsenic. Several lines of evidence show that the important acceptor impurities zinc and cadmium are volatile from molten indium antimonide. The removal of acceptors by volatilization under appropriate experimental conditions, followed by zone refining, can yield material with less than 1014 excess donors per cm3.