vapor cocrystallization accompanied by decomposition of the initial form of the minor component. part 2. cocrystallization of 55FeCl3 and 55FeCl2 with ZrCl4

The radionuclide 55Fe has been used to examine the distribution under static conditions of traces of iron added in the form of FeCl3 between ZrCl4 crystals and vapor at 240-3100C. The level of the minor component was 0.2-0.6 mol. %. Mossbauer spectroscopy has been employed with iron specimens enriched in 57Fe to show that the iron is taken up by ZrCl4 mainly as FeCl2 if elemental chlorine is not especially added, this compound being formed by the decomposition of FeCl3 to FeCl2 and Cl2. If the decomposition is suppressed by adding chlorine, the iron is taken up mainly as FeCl3. Measurements have been made on the cocrystallization coefficients for FeCl2 and FeCl3, namely D /SUB FeCl/ 2 and D /SUB FeCl/ 3, where DFeCl2 >> DFeCl3 at any given temperautre