Partial oxygen pressure and temperature effects on the oxygen content of the Y–Ba–Cu–O melts
| Autor: | G. F. Voronin, E.C. Beahm, R.D. Hunt |
|---|---|
| Rok vydání: | 1998 |
| Předmět: |
Materials science
Hydrogen Analytical chemistry Energy Engineering and Power Technology chemistry.chemical_element Liquidus Partial pressure Condensed Matter Physics Electrochemistry Oxygen Electronic Optical and Magnetic Materials chemistry Phase (matter) Gravimetric analysis Electrical and Electronic Engineering Phase diagram |
| Zdroj: | Physica C: Superconductivity. 302:130-136 |
| ISSN: | 0921-4534 |
| DOI: | 10.1016/s0921-4534(98)00201-9 |
| Popis: | The oxygen content and phase transition temperatures of equilibrated samples with Y:Ba:Cu:O molar ratios of 1:2:3: n (YBa 2 Cu 3 O x phase) and 1:3:4: n (YBa 2 Cu 3 O x +BaCuO 2 phases) were determined with a differential thermal analyzer (DTA), a thermal gravimetric analyzer (TGA) and an electrochemical oxygen analyzer. These Y–Ba–Cu–O melts were studied at partial oxygen pressures that ranged from 1×10 5 to 6 Pa and at temperatures from 1200 to 1580 K. The oxygen contents of these melts were determined with hydrogen reduction and the TGA. The oxygen content of the 1:2:3: n melts decreased as the temperature increased and as the partial oxygen pressure decreased. The same pattern for the partial oxygen pressure was observed for the oxygen content in the 1:3:4: n melts. However, at a given partial oxygen pressure, the highest oxygen content in a 1:3:4: n melt was observed at a temperature approximately 100 K above the initial melting temperature. The liquidus temperatures for 1:2:3: n and 1:3:4: n always decreased as the partial oxygen pressures decreased. Finally, the compositions of the melts, which included the formation of YBa 3 Al 2 O 7.5 in the 1:3:4: n melts, are also discussed. |
| Databáze: | OpenAIRE |
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