| Autor: |
K Rubešová, O Smrčková, D. Sýkorová, K Knı́žek |
| Rok vydání: |
2002 |
| Předmět: |
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| Zdroj: |
Physica B: Condensed Matter. 321:295-297 |
| ISSN: |
0921-4526 |
| DOI: |
10.1016/s0921-4526(02)00864-5 |
| Popis: |
Samples with partial cationic substitution for bismuth in Bi(Pb)-Sr-Ca-Cu-O system were prepared to systematically examine phase formation due to different concentrations of B, Al, Ga and In. The elements were substituted in the range x = 0-0.5 in the nominal formula Bi 1.8-x A x Pb 0.26 Sr 2 Ca 2 Cu 3 O y . X-ray diffraction analysis was carried out for phase analysis with special emphasis to detect impurity phases. All the samples were mixed phases of 2212 and 2223. Rietveld analysis was used to find out the ratio of the phases. Boron enhanced the formation of the 2223 phase up to x = 0.5, but gallium deteriorated the high-temperature phase 2223 and the 2212 phase became dominant. The amount of 2223 phase was increased with increasing content of Al and In (up to x = 0.2) and then was decreased. The lattice parameters of the superconducting phases were obtained, and no systematic variations with the dopant level were found. Scanning electron microscopy observations revealed the presence of small and irregular amounts of Ga and In in the chemical composition of superconducting grains and the existence of the various non-superconducting phases. Superconducting properties of the samples were characterized by the measurement of the temperature dependence of the electrical and magnetic properties. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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