Thermodynamic and nonstoichiometric behavior of the GdBa{sub 2}Cu{sub 3}O{sub x} system.
Electromotive force (EMF) measurements of oxygen fugacities as a function of stoichiometry have been made on the GdBa{sub 2}Cu{sub 3}O{sub x} system in the temperature range {approximately}400-600 C by means of an oxygen titration technique with an yttria-stabilized zirconia electrolyte. Equations for the variation of oxygen partial pressure with composition and temperature have been derived from our EMF measurements. The shape of the 400 C isotherms as a function of oxygen stoichiometry for the Gd and Nd cuprate systems suggests the presence of miscibility gaps at values of x that are higher than those in the YBa{sub 2}Cu{sub 3}O{sub x} system. For a given oxygen stoichiometry, oxygen partial pressures above Gd-123 and Nd-123 cuprate systems are higher (above x = 6.5) than that for the Y-123 system. A thermodynamic assessment and intercomparison of our partial pressure measurements with the results of related measurements will be presented.
- Research Organization:
- Argonne National Lab., IL (US)
- Sponsoring Organization:
- US Department of Energy (US)
- DOE Contract Number:
- W-31109-ENG-38
- OSTI ID:
- 10988
- Report Number(s):
- ANL/CMT/CP-97381
- Country of Publication:
- United States
- Language:
- English
Similar Records
Thermodynamic behavior of high-T sub c oxide systems via EMF and related measurements
Oxygen stoichiometry, structural transitions, and thermodynamic behavior of the YBa sub 2 Cu sub 3 O sub x system