Phase equilibria and magnetism in the Mo–Si–U system

Phase equilibria in the system Mo–Si–U were established at 1400°C for the region less than 60 at.% U and at 850°C for the region less than 70 at.% Si by optical microscopy, EMPA and X-ray diffraction. Three ternary compounds were observed and characterised by X-ray powder or single-crystal data refinement: (1) stoichiometric U2Mo3Si4 (U2Mo3Si4-type); (2) U(Mo1−xSix)2 (MgZn2-type) extending at 1400°C from U(Mo0.62Si0.38)2 to U(Mo0.75Si0.25)2 but with a small field of existence at 850°C around U(Mo0.68Si0.32)2 and (3) U4Mo(MoxSi1−x)1Si2 (ordered structure variant of W5Si3-type) extending at 850°C from x=0 to x=0.33. The magnetic behaviour of the three compounds is characterised by temperature independent paramagnetism.