On the Formation of UC_1-x N_x

Abstract

From the known values of the free energy of formation of several uranium compounds in the ternary system U-C-N, the condition of stable existence of the solid solution between UC and UN, UC1-xNx' was determined, and several ternary sections were obtained at constant temperature and constant nitrogen pressure.
In order to examine these results, some experiments were carried out under several different conditions of temperature and nitrogen pressure.
From these results, it is concluded that the stable compounds which exist in the ternary system U-C-N change from larger to smaller value of (log P_N2)/T in the following order;
(1) U₂N₃ and carbon
(2) UC_1-xN_x and carbon
(3) UC_1-xN_x and carbon
(4) UC_1-xN_x' UC2 and metallic uranium
(5) Under the condition of high temperature and low pressure, that is, a very small ill valueof (log P_N2)/T, tha range of stable existence of the solid solution, UC_1-xN_x' is very small.