P. Gadd, H. Borgstedt
Dec 1, 1983
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Influential Citations
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Journal
Journal of Nuclear Materials
Abstract
Abstract Results from a study of the Rb-Cr-O system in the presence of liquid rubidium metal are presented. Compound formation in the system was studied by means of bulk reactions between various chromium oxides and rubidium metal at 500° C followed by vacuum distillation of the excess metal and X-ray powder diffraction analysis of the residues. Equilibrium oxygen potential measurements of Rb-O solutions in contact with chromium metal or chromium compounds using an electrochemical oxygen meter (ThO 2 /7.5 wt%Y 2 O 3 electrolyte, Sn/SnO 2 reference electrode) gave information on the stability and conditions of formation of these compounds in the liquid. The investigations showed that Cr metal getters oxygen from rubidium to form a compound (possibly RbCrO 2 ) in equilibrium with low oxygen activities ( a 0 = 5.43 × 10 −7 , 500°C ). At higher oxygen levels, however, the formation of Rb 4 CrO 4 takes place. A metastable phase Rb 3 CrO 4 was also observed in some bulk reactions.