Compatible phases of the Y sub 2 O sub 3 --CuO--Cu sub 2 O system in air

Journal Article · Thu Feb 28 23:00:00 EST 1991 · Journal of Materials Research; (USA)

DOI:https://doi.org/10.1557/JMR.1991.0450· OSTI ID:5735910

Gadalla, A M; Kongkachuichay, P ^[1]

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1. Chemical Engineering Department, Texas A M University, College Station, Texas 77843 (US)

The phase diagram of the Y{sub 2}O{sub 3}--CuO--Cu{sub 2}O system was constructed as a function of temperature in air by means of thermal analysis and x-ray diffraction. The phase Y{sub 2}Cu{sub 2}O{sub 5} was found to be stoichiometric and melted peritectically at about 1110 {degree}C. A new intermediate phase with the composition YCu{sub 2}O{sub 2.5} was discovered. It exists between 990 and 1105 {degree}C in air and quenching did not preserve it to room temperature. High temperature x-ray diffraction established its pattern and confirmed its peritectic decomposition. Above 1110 {degree}C YCu{sub 2}O{sub 2.5} consists of Y{sub 2}O{sub 3} and liquid. The results of this system are shown on a ternary system as well as on a pseudo-binary phase diagram. The solid state reations were established. Melting occurs with isothermal oxygen loss or gain, depending on the initial composition.

• OSTI ID: 5735910
• Journal Information: Journal of Materials Research; (USA), Journal Name: Journal of Materials Research; (USA) Vol. 6:3; ISSN JMREE; ISSN 0884-2914
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360202* -- Ceramics
Cermets
& Refractories-- Structure & Phase Studies
AIR
CHALCOGENIDES
COHERENT SCATTERING
COPPER COMPOUNDS
COPPER OXIDES
DIAGRAMS
DIFFRACTION
FLUIDS
GASES
MELTING
OXIDES
OXYGEN COMPOUNDS
PHASE DIAGRAMS
PHASE TRANSFORMATIONS
SCATTERING
STOICHIOMETRY
TEMPERATURE DEPENDENCE
TRANSITION ELEMENT COMPOUNDS
VERY HIGH TEMPERATURE
X-RAY DIFFRACTION
YTTRIUM COMPOUNDS
YTTRIUM OXIDES