| Autor: |
A. Nafidi, B. Bouallal, A. El Kaaouachi, H. Chaib, M. Bellioua, U. (Balu) Balachandran, Kathleen Amm, David Evans, Eric Gregory, Peter Lee, Mike Osofsky, Sastry Pamidi, Chan Park, Judy Wu, Mike Sumption |
| Rok vydání: |
2008 |
| Předmět: |
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| Zdroj: |
AIP Conference Proceedings. |
| ISSN: |
0094-243X |
| DOI: |
10.1063/1.2900396 |
| Popis: |
We report here on the preparation, X‐ray diffraction with Rietveld refinement, AC susceptibility measurements and effect of heat treatments in (Y1−xEux)(SrBa)Cu3O6.94. Each sample was subject to two types of heat treatment: oxygen annealing [O] and argon annealing followed by oxygen annealing [AO]. When x increase from 0 to 1, the orthorhombicity e = (b−a)/(b+a) decreases with Tc[O]. However, Tc[AO] decreases with e until x = 0.2 and after it increases by 7 K to 87 K for x = 1 [A,O]. The crystalline parameter b is constant but a (and c) increase indicating an increase of the number of oxygen atoms by chain (NOC) along a axis leading to a decrease of e (Tc) [O] toward a tetragonal structure. The cationic disorder along c decreased for x⩾0.45. For each x, the [AO] treatment increases e (for 0⩽x⩽1), Tc (for x⩾0.45) and the distance d[Cu(1)‐O1] (decrease Tc) for x 0.45. Remarkable correlations were observed. A combination of several factors such as decrease in d[Cu (1)... |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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