Plasma-chemical purification of iodine

Abstract The aim of this work is to suggest a novel approach to purification of iodine especially designed for the production of semiconductors and optical materials of the IR range. For the first time iodine has been purified via intermediate plasma-chemical formation of diiodine oxides and followed by their thermal decomposition with the formation of high-purity iodine and oxygen. The process of iodine oxidation included direct interaction of iodine vapours with oxygen-argon plasma feed gas mixtures at low pressure (0.1 Torr) in inductively coupled non-equilibrium RF (40.68 MHz) plasma discharge. The new method is aiming to reduce both the metal and the carbon-containing impurities that behaviour was also studied. A possible mechanism of impurities conversion during the process was suggested.