Abstract
Phase relations in the dry condensed Fe-Ir-S system were determined at 1100, 1000 and 800 degrees C. Orientational runs were performed at 500 degrees C. Between 1100 and 800 degrees C, the system comprises five sulphides and an uninterrupted field of gamma (Fe,Ir). Fe (sub 1-x) S dissolves 5.8 at.% Ir at 1100 degrees C, 3.4 at.% Ir at 1000 degrees C and 1.0 at.% Ir at 800 degrees C. The solubility of Fe in Ir 2 S 3 , IrS 2 and IrS (sub approximately 3) increases with decreasing temperature, reaching 2.5 at.% in the latter two sulphides at 800 degrees C. Thiospinel "FeIr 2 S 4 " is non-stoichiometric, from Fe (sub 22.3) Ir (sub 19.8) S (sub 58.0) to Fe (sub 18.9) Ir (sub 23.1) S (sub 58.0) , depending on a s and a Fe i.e. on a phase association. Thiospinel is absent at 800 and 500 degrees C.