Oxidation-reduction in the mixed (Cf,Bk)Osub(x) system

This work describes oxidation-reduction behavior of Cf in two different compositions of the solid solution (Cf,Bk)Osub(x). Lattice parameter measurements taken at high temperature and controlled oxygen activity show that in relatively dilute solid solution (25% Cf), the complete 3+ - 4+ field is crossed between 200 and 6000C. When Cf is the dominant cation (64%), the formation of M7O12 apparently controls oxidation state changes as in the pure oxide, limiting the Cf state to Cfsup(3.3+) in approximately 105 Pa O2. (author)