Effect of Ar heat treatment on oxygenated R<subscript>1− x</subscript>Ca<subscript> x</subscript>Ba<subscript>2</subscript>Cu<subscript>3</subscript>O<subscript>7−δ</subscript> (R = Y, Sm) superconductors.
In: Journal of Materials Science, Jg. 37 (2002-04-15), Heft 8, S. 1557-1560
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Zugriff:
The influence of heat treatment, at 450°C in Ar environment, on oxygenated (6.72 < 7 − δ < 6.93) samples of R 1− x Ca x Ba 2 Cu 3 O 7−δ (i.e. R(Ca)-123, with R = Y, Sm) with 0 < x < 0.3 has been investigated. Measurements of oxygen loss, normal state resistivity behaviour ρ( T), superconducting critical temperature T c and transition widths reveal that Ar treatment effects both the series differently. The Sm(Ca)-123 samples, for all values of x, show a considerable loss of oxygen (Δδ( x) = 0.4 to 0.6) and decrease in T c (Δ T c ( x) = 35 to 55 K). Whereas, surprisingly, the Y(Ca)-123 samples show a much smaller loss of oxygen (Δδ( x) = 0 to 0.3), along with a decrease in T c for x < 0.2 and an increase in it for x > 0.2. In particular, the x = 0.3 sample shows a negligible change in oxygen content accompanied by an increase of 20 K in T c . These and host of other observations suggest that the presence of Ca may influence the oxygen loss mechanism in these series. [ABSTRACT FROM AUTHOR]
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Titel: |
Effect of Ar heat treatment on oxygenated R<subscript>1− x</subscript>Ca<subscript> x</subscript>Ba<subscript>2</subscript>Cu<subscript>3</subscript>O<subscript>7−δ</subscript> (R = Y, Sm) superconductors.
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Autor/in / Beteiligte Person: | Gupta, Anurag ; Sedky, A. ; Narlikar, A. V. ; Singh, D. P. |
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Zeitschrift: | Journal of Materials Science, Jg. 37 (2002-04-15), Heft 8, S. 1557-1560 |
Veröffentlichung: | 2002 |
Medientyp: | academicJournal |
ISSN: | 0022-2461 (print) |
DOI: | 10.1023/A:1014925020459 |
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