CURIUM-OXYGEN SYSTEM

Oxygen vapor pressures have been measured over nonstoichiometric curium oxides in the temperature and pressure intervals of 300-900°C and 2-730 mm O2. The resulting isobaric temperature-composition plots allowed deductions concerning the nature of the phase equilibria in the curium-oxygen system. The postulated phase diagram is characterized by two intermediate phases occurring at CmO1·72 and CmO1·82, while additional nonstoichiometric phases occur near the dioxide and sesquioxide compositions. All of the isobars showed pronounced hysteresis loops in the diphasic regions during heating and cooling cycles. © 1969.