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Updated: Dec 31, 2025

The Synthesis, Characterization and Reactivity of a Series of Ruthenium N-triphosPh Complexes
Published on: April 10, 2015
Phase Relations in the Ru-lr-O2 System in Air
1Institute for Materials Research, National Bureau of Standards, Washington, D.C. 20234.
Abstract:
The equilibrium phase relations were determined in an air environment for the system Ru-Ir-O2. In air Ru oxidizes at moderate temperatures, to form RuO2, which in turn dissociates at 1405 °C. Similarly Ir oxidizes to form IrO2 and dissociates at 1020 °C. The dissociation of RuO2 and IrO2 are reversible processes. A ternary equilibrium phase diagram was constructed indicating selected oxygen reaction lines and isotherms. A binary representation of the Ru-Ir-O2 system in air is given. Up to 1020 °C, RuO2 reacts with IrO2 to form a complete solid solution series having the rutile-type structure. At 134S °C three solid phases, rutiless, Russ, and Irss, exist in equilibrium for compositions between approximately 2 and 45 mole percent IrO2. Above 1405 °C dissociation is complete for all compositions and the phase relations are represented by the Ru-Ir system. At 1500 °C solid solution of Ru and Ir occurs with the addition of up to 45 mole percent Ir and up to 44 mole percent Ru, respectively.
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