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Updated: Dec 31, 2025
10:51
The Synthesis, Characterization and Reactivity of a Series of Ruthenium N-triphosPh Complexes
Published on: April 10, 2015
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Phase Relations in the Ru-lr-O2 System in Air.
1Institute for Materials Research, National Bureau of Standards, Washington, D.C. 20234.
Summary
The Ru-Ir-O2 system in air shows RuO2 and IrO2 form solid solutions below 1020°C. At higher temperatures, phase equilibria shift, leading to Ru-Ir solid solutions above 1405°C.
Area of Science:
- Materials Science
- Solid State Chemistry
- Chemical Thermodynamics
Background:
- Ruthenium (Ru) and Iridium (Ir) oxides exhibit complex phase behaviors under varying temperatures.
- Understanding these phase relations is crucial for applications involving high-temperature materials and catalysis.
- The Ru-Ir-O2 system's equilibrium in air requires detailed investigation.
Purpose of the Study:
- To determine the equilibrium phase relations in the Ru-Ir-O2 system in an air environment.
- To construct a ternary equilibrium phase diagram with selected oxygen reaction lines and isotherms.
- To provide a binary representation of the Ru-Ir-O2 system in air.
Main Methods:
- Experimental determination of equilibrium phase relations in air.
- Construction of ternary and binary phase diagrams.
- Analysis of phase transformations at various temperatures and compositions.
Main Results:
- RuO2 and IrO2 form a complete solid solution series with a rutile-type structure up to 1020°C.
- At 1345°C, three solid phases (rutiless, Russ, Irss) coexist between 2 and 45 mole percent IrO2.
- Above 1405°C, complete dissociation occurs, and phase relations are governed by the Ru-Ir binary system, showing significant solid solution formation at 1500°C.
Conclusions:
- The Ru-Ir-O2 system exhibits distinct phase equilibria dependent on temperature and oxygen partial pressure (in air).
- Solid solution formation is a key feature across different temperature regimes.
- The study provides a comprehensive phase diagram essential for predicting material behavior in relevant environments.
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