Abstract
For a consistent thermodynamic description of the quaternary system Y-Ba-Cu-O, the binary and ternary subsystems must be known. The metallic binaries and the ternary system Y-Ba-Cu have been evaluated by the authors. Discrepancies within the Cu-O system made a thorough experimental re-investigation necessary, leading to a new consistent thermodynamic data set for copper-oxygen which can now serve as a basis for the description of phase equilibria of all high temperature superconductors. Extensive experimental work on the ternaries Y-Cu-O and Ba-Cu-O, which are oxygen partial pressure dependent, revealed liquid phases down to 790degC. The ternary Y-Ba-O could be described more easily on the basis of literature values and present experimental results, because it does not contain any liquid phases at relevant temperatures. The representation of the quaternary Y-Ba-Cu-O is complicated both by its dependence on the oxygen potential and the existence of liquid oxide phases. In contrast to common practice, the present investigations had to start from Cu-free Ba-Y-O in order to avoid unknown liquid phases in the experiments. The present results being insufficient for a complete description of the quaternary system, the work is being continued within an EC joint research project. (orig.) With 84 refs., 8 tabs., 47 figs.
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Citation Formats
Neuschuetz, D, Zimmermann, E, Hack, K, Boudene, A, and Mohammad, A.
Thermochemical investigations into the system Y-Ba-Cu-O. Final report; Thermochemische Untersuchungen am System Y-Ba-Cu-O. Schlussbericht.
Germany: N. p.,
1992.
Web.
Neuschuetz, D, Zimmermann, E, Hack, K, Boudene, A, & Mohammad, A.
Thermochemical investigations into the system Y-Ba-Cu-O. Final report; Thermochemische Untersuchungen am System Y-Ba-Cu-O. Schlussbericht.
Germany.
Neuschuetz, D, Zimmermann, E, Hack, K, Boudene, A, and Mohammad, A.
1992.
"Thermochemical investigations into the system Y-Ba-Cu-O. Final report; Thermochemische Untersuchungen am System Y-Ba-Cu-O. Schlussbericht."
Germany.
@misc{etde_10136229,
title = {Thermochemical investigations into the system Y-Ba-Cu-O. Final report; Thermochemische Untersuchungen am System Y-Ba-Cu-O. Schlussbericht}
author = {Neuschuetz, D, Zimmermann, E, Hack, K, Boudene, A, and Mohammad, A}
abstractNote = {For a consistent thermodynamic description of the quaternary system Y-Ba-Cu-O, the binary and ternary subsystems must be known. The metallic binaries and the ternary system Y-Ba-Cu have been evaluated by the authors. Discrepancies within the Cu-O system made a thorough experimental re-investigation necessary, leading to a new consistent thermodynamic data set for copper-oxygen which can now serve as a basis for the description of phase equilibria of all high temperature superconductors. Extensive experimental work on the ternaries Y-Cu-O and Ba-Cu-O, which are oxygen partial pressure dependent, revealed liquid phases down to 790degC. The ternary Y-Ba-O could be described more easily on the basis of literature values and present experimental results, because it does not contain any liquid phases at relevant temperatures. The representation of the quaternary Y-Ba-Cu-O is complicated both by its dependence on the oxygen potential and the existence of liquid oxide phases. In contrast to common practice, the present investigations had to start from Cu-free Ba-Y-O in order to avoid unknown liquid phases in the experiments. The present results being insufficient for a complete description of the quaternary system, the work is being continued within an EC joint research project. (orig.) With 84 refs., 8 tabs., 47 figs. [Deutsch] Fuer eine konsistente thermodynamische Beschreibung des quaternaeren Systems Y-Ba-Cu-O muessen die binaeren und ternaeren Randsysteme bekannt sein. Die binaeren metallischen Teilsysteme und das ternaere metallische System Y-Ba-Cu wurden am Lehrstuhl ausgewertet. Wegen auftretender Diskrepanzen wurden zum System Cu-O eingehende experimentelle Untersuchungen erforderlich. Sie fuehrten zu einer neuen konsistenten thermodynamischen Beschreibung des Systems Kupfer-Sauerstoff, die nunmehr als Basis der Phasengleichgewichte aller Hochtemperatur-Supraleiter dienen kann. Umfangreiche experimentelle Untersuchungen zu den sauerstoffdruckabhaengigen ternaeren Systemen Y-Cu-O und Ba-Cu-O zeigten, dass hier schmelzfluessige Phasen bis herunter zu 790deg C existieren. Das ternaere System Y-Ba-O liess sich aus Literaturangaben und eigenen Messungen einfacher beschreiben, da keine Schmelzphasen auftraten. Die Darstellung des quaternaeren Systems Y-Ba-Cu-O wird durch den starken Einfluss des Sauerstoffpotentials und das Auftreten fluessiger Oxidphasen erschwert. Im Gegensatz zur bisherigen Praxis mussten die Versuche von kupferfreiem Ba-Y-O ausgehen, um unbekannte Schmelzphasen zu vermeiden. Die so durchgefuehrten Messungen reichen gegenwaertig zur thermodynamischen Beschreibung des Gesamtsystems noch nicht aus. Die Arbeiten werden im Rahmen eines EG-Verbundprojektes fortgesetzt. (orig.) With 84 refs., 8 tabs., 47 figs.}
place = {Germany}
year = {1992}
month = {Dec}
}
title = {Thermochemical investigations into the system Y-Ba-Cu-O. Final report; Thermochemische Untersuchungen am System Y-Ba-Cu-O. Schlussbericht}
author = {Neuschuetz, D, Zimmermann, E, Hack, K, Boudene, A, and Mohammad, A}
abstractNote = {For a consistent thermodynamic description of the quaternary system Y-Ba-Cu-O, the binary and ternary subsystems must be known. The metallic binaries and the ternary system Y-Ba-Cu have been evaluated by the authors. Discrepancies within the Cu-O system made a thorough experimental re-investigation necessary, leading to a new consistent thermodynamic data set for copper-oxygen which can now serve as a basis for the description of phase equilibria of all high temperature superconductors. Extensive experimental work on the ternaries Y-Cu-O and Ba-Cu-O, which are oxygen partial pressure dependent, revealed liquid phases down to 790degC. The ternary Y-Ba-O could be described more easily on the basis of literature values and present experimental results, because it does not contain any liquid phases at relevant temperatures. The representation of the quaternary Y-Ba-Cu-O is complicated both by its dependence on the oxygen potential and the existence of liquid oxide phases. In contrast to common practice, the present investigations had to start from Cu-free Ba-Y-O in order to avoid unknown liquid phases in the experiments. The present results being insufficient for a complete description of the quaternary system, the work is being continued within an EC joint research project. (orig.) With 84 refs., 8 tabs., 47 figs. [Deutsch] Fuer eine konsistente thermodynamische Beschreibung des quaternaeren Systems Y-Ba-Cu-O muessen die binaeren und ternaeren Randsysteme bekannt sein. Die binaeren metallischen Teilsysteme und das ternaere metallische System Y-Ba-Cu wurden am Lehrstuhl ausgewertet. Wegen auftretender Diskrepanzen wurden zum System Cu-O eingehende experimentelle Untersuchungen erforderlich. Sie fuehrten zu einer neuen konsistenten thermodynamischen Beschreibung des Systems Kupfer-Sauerstoff, die nunmehr als Basis der Phasengleichgewichte aller Hochtemperatur-Supraleiter dienen kann. Umfangreiche experimentelle Untersuchungen zu den sauerstoffdruckabhaengigen ternaeren Systemen Y-Cu-O und Ba-Cu-O zeigten, dass hier schmelzfluessige Phasen bis herunter zu 790deg C existieren. Das ternaere System Y-Ba-O liess sich aus Literaturangaben und eigenen Messungen einfacher beschreiben, da keine Schmelzphasen auftraten. Die Darstellung des quaternaeren Systems Y-Ba-Cu-O wird durch den starken Einfluss des Sauerstoffpotentials und das Auftreten fluessiger Oxidphasen erschwert. Im Gegensatz zur bisherigen Praxis mussten die Versuche von kupferfreiem Ba-Y-O ausgehen, um unbekannte Schmelzphasen zu vermeiden. Die so durchgefuehrten Messungen reichen gegenwaertig zur thermodynamischen Beschreibung des Gesamtsystems noch nicht aus. Die Arbeiten werden im Rahmen eines EG-Verbundprojektes fortgesetzt. (orig.) With 84 refs., 8 tabs., 47 figs.}
place = {Germany}
year = {1992}
month = {Dec}
}