Open AccessPhase relations in the SrO-IrO2-Ir system in air
Author(s) -
C.L. McDaniel,
Samuel J Schneider
Publication year - 1971
Publication title -
journal of research of the national bureau of standards. section a. physics and chemistry
Language(s) - English
Resource type - Journals
eISSN - 2376-5704
pISSN - 0022-4332
DOI - 10.6028/jres.075a.019
Subject(s) - metastability , phase diagram , atmospheric pressure , ternary operation , phase (matter) , binary number , thermodynamics , materials science , chemistry , physics , computer science , mathematics , meteorology , arithmetic , organic chemistry , programming language
The equilibrium phase relations for the SrO-IrO 2 -Ir system were determined in an air environment at atmospheric pressure. A ternary equilibrium phase diagram was constructed indicating selected oxygen reaction lines and tie lines. A binary representation is given for the ternary system in air. Of the nine phases detected in this study, three are stable and six are probably metastable under atmospheric conditions. The stable compounds, 4SrO · IrO 2 , 2SrO · IrO 2 , and SrO · IrO 2 dissociate at 1540, 1445, and 1205 °C, respectively. The metastable phases include low-4SrO · IrO 2 , 2SrO · 3IrO 2 , x SrO · IrO 2 ( x > 2), y SrO · IrO 2 (4 > y > 2), z SrO · IrO 2 (2 > z > 1), and 3SrO · 2IrO 2 . The specific composition of the metastable phases could not be ascertained with certainty. The x-ray patterns of all phases detected in this study were indexed with the exception of that of the z SrO · IrO 2 (2 > z > 1) compound. A summary of x-ray data is given for all known phases occurring in the system.