Abstract
The UC-UN solid solution, UC1-xNx, exists stably in monophase within a certain range of nitro-gen pressure at constant temperature. At the upper limit of this range, UC1-xNx coexists with UC2 or with carbon, and it precipitates metallic uranium at the lower limit which corresponds to the de-composition pressure of UC1-xNx.
In order to measure the decomposition temperature of UC1-xNx with given x under constant nitrogen pressure, it is necessary to heat UC1-xNx without changing its composition, at a constant pressure.
In the present work, preliminary considerations have been given to change in composition. Ex-periments were also performed in which the solid solution was heated at a rate of 200°C/min under different nitrogen pressures.
From the results, it is concluded that there exists a temperature range within which the value of x in UC1-xNx is maintained constant when the nitrogen pressure is fixed.
