Phase diagram of the UO2–FeO1+x system

Phase-relation studies of the UO2–FeO1+x system in an inert atmosphere are presented. The eutectic point has been determined, which corresponds to a temperature of (1335 ± 5) °C and a UO2 concentration of (4.0 ± 0.1) mol.%. The maximum solubility of FeO in UO2 at the eutectic temperature has been estimated as (17.0 ± 1.0) mol.%. Liquidus temperatures for a wide concentration range have been determined and a phase diagram of the system has been constructed.