Oxygen stoichiometry, phase stability, and thermodynamic behavior of the lead-doped Bi-2223 and Ag/Bi-2223 systems
| Autor: | Victor A. Maroni, B.S. Tani, J.S. Luo, M. Tetenbaum, M.C. Hash |
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| Rok vydání: | 1995 |
| Předmět: |
Materials science
Electromotive force Analytical chemistry Energy Engineering and Power Technology chemistry.chemical_element Partial molar property Partial pressure Electrolyte Atmospheric temperature range Condensed Matter Physics EMF measurement Oxygen Electronic Optical and Magnetic Materials chemistry Electrical and Electronic Engineering Stoichiometry |
| Zdroj: | Physica C: Superconductivity. 249:396-402 |
| ISSN: | 0921-4534 |
| Popis: | Electromotive-force (EMF) measurements of oxygen fugacities as a function of stoichiometry have been made in the lead-doped Bi-2223 superconducting system in the temperature range 700–815°C by means of an oxygen titration technique that employs an yttria-stabilized zirconia electrolyte. The results of our studies indicate that processing or annealing lead-doped Bi-2223 at temperatures ranging from 750 to 815°C and at oxygen partial pressures ranging from ∼ 0.02 to 0.2 atm should preserve Bi-2223 as essentially single-phase material. Thermodynamic assessments of the partial molar quantities Δ S ( O 2 ) and Δ H ( O 2 ) indicate that the plateau regions in the plot of oxygen partial pressure versus oxygen stoichiometry (x) can be represented by the diphasic CuOCu2O system. In accord with the EMF measurements, it was found that lead-doped Bi-2223 in a silver sheath is stable at 815°C for oxygen partial pressures between 0.02 and 0.13 atm. |
| Databáze: | OpenAIRE |
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