| Autor: |
E. Norkus, Arturas Zalga, J. Reklaitis, Aivaras Kareiva, Aldona Beganskiene |
| Rok vydání: |
2006 |
| Předmět: |
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| Zdroj: |
Chemical Physics. 327:220-228 |
| ISSN: |
0301-0104 |
| DOI: |
10.1016/j.chemphys.2006.04.007 |
| Popis: |
The aqueous sol–gel synthesis technique for the preparation of YBa2Cu4O8 (Y-124) superconductor was studied using two different complexing agents with the same chemical composition, namely l -(+)-tartaric (natural) and dl -tartaric (synthetic) acids. The characterization of Y–Ba–Cu–O gels by XRD and TGA/DTA measurements showed the individuality of precursor gels and a high level of homogeneity. On the other hand, the morphological features of the gels observed by SEM measurements were slightly different. The ceramic samples calcined for 30 h at 780 °C in a flowing oxygen atmosphere contained homogeneous Y-124 crystallites as a major phase, as was shown by XRD analysis. The TC (onset) observed by resistivity and magnetic susceptibility measurements was approximately the same for the both samples (78–80 K). However, the temperature–resistivity and temperature–magnetic susceptibility dependences were found to be different for the Y-124 samples synthesized by different sol–gel procedures. Such behaviour was discussed in correlation with the morphological properties of the prepared samples. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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