-28 METHOD FOR THE PRODUCTION OF SINGLE ISOTOPIC SILICON Si-28

摘要

Field of the Invention The present invention relates to the field of metallurgy,²⁸ RTI ID = 0.0 mono isotopic /RTI silicon from tetrafluoride silicon. The method comprises reducing the tetrafluoride silicon at a high temperature and reducing the silane from the tetrafluoride silicon by reducing the tetrafluoride silicon with calcium hydride at a temperature of 180C to 200C . The obtained silane undergoes high temperature decomposition at a temperature of 800C to 900C and the sedimentation rate on the base layer of monoisotopic silicone is not greater than 0.5mm per hour. The precipitation of monoisotopic silicon on the base layer is preferentially controlled by varying the feed rate of the silane. The precipitation is affected by the base layer of mono isotopic silicon obtained preliminarily or by two steps. The precipitate in the first step is formed in a heat-resistant base layer, for example, a metal having a melting point higher than the temperature of the silicon precipitate. Then, the obtained monoisotropic silicon bar is separated from the base layer and the precipitation process is continued as obtained in the first step. The final bars are subjected to high purification, preferably by crucibleless zone melting method.