Gaseous Buffering for the Control of Oxygen Fugacity at One Atmosphere

摘要: The importance of controlling fugacitiesl when studying reactions in closed systems which involve elements whose oxidation states are otherwise readily changed at high temperatures is well known. Perhaps the most important these transition iron, due large part to its widespread technological uses and natural occurrences. Osborn Muan (1963), for example, illustrated oxygen fugacity (fO2) on liquidus liquids system FeO-Fe2O3-SiO2. Crystallization sequences under various fO2 conditions this were discussed by (1955). Comprehensive discussions concerning Fe-O given elsewhere (Darken Gurry, 1945, 1946; Muan, 1958; 1963; Osborn, 1965). Nickel, cobalt, manganese, chromium, vanadium their oxide compounds have all become materials present day technology (e.g., stainless steels, super-strength alloys, magnetic magnets, cermets, ferrites). Oxygen control involving such variable state important. This has been emphasized literature (see examples, Hahn 1961, nickel; Masse et al., 1966, cobalt; Davies Richardson, 1959, Morris Glasser, 1958, manganese; Johnson 1968, Graham Davis, 1971, chromium; Katsura Hasegawa, 1967, vanadium).