Nitride-forming behavior in liquid cadmium-uranium-lanthanides alloys

The nitride formation reaction of liquid 2 wt% U-1 wt% Gd-1 wt% Ce-Cd alloys has been studied over the temperature range of 773 73 K using graphite and molybdenum crucibles. The Cd-U alloys were contacted with nitrogen gas or Li3N. Uranium in the liquid Cd alloy was preferentially nitrided to form U2N3, which were produced at nitrogen gas-liquid alloy interface. A little gadolinium precipitated as nitrides, GdN or (U,Gd)N phase. The rest of gadolinium and almost all of cerium remained in the Cd phase as MCd11 (M: Gd and Ce) intermetallic compounds. Resistance of Ce to nitridation is due to the lower activity coefficient in Cd-rich solution at the temperatures. (authors)