Low-field microwave absorptions of silver-doped yttrium barium copper oxide (YBa2Cu3O7-.delta.) superconductors
| Autor: | Larry Kevan, John L. Bear, S. Marrelli, S. O'connor, Micky Puri, J. Masiakowski |
|---|---|
| Rok vydání: | 1991 |
| Předmět: |
chemistry.chemical_classification
Superconductivity High-temperature superconductivity Absorption spectroscopy General Engineering Analytical chemistry Physics::Optics Mineralogy Grain size law.invention Condensed Matter::Materials Science chemistry Electrical resistivity and conductivity law Condensed Matter::Superconductivity Content (measure theory) Physics::Atomic and Molecular Clusters Physical and Theoretical Chemistry Penetration depth Inorganic compound |
| Zdroj: | The Journal of Physical Chemistry. 95:1152-1159 |
| ISSN: | 1541-5740 0022-3654 |
| DOI: | 10.1021/j100156a024 |
| Popis: | Superconducting and microstructural properties of silver-doped YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} composites have been studied as a function of silver content. An increase by {approximately}8 K in the superconducting transition temperature is observed by resistance measurement above 4.2 wt % silver. Silver seems to act as a flux to propagate the formation of oblong-shaped grains. The grain size increases with silver doping, and at high concentrations of silver it also induces grain alignment. Silver is not observed to substitute for Cu in YBa{sub 2}Cu{sub 3}O{sub 7-{delta}}. Low-field microwave absorption (LFMA) shows different hysteresis and power dependence behavior between YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} and silver-doped samples. The LFMA signal intensity decreases with increasing silver content, and the maximum response shifts to higher temperature. The LFMA signal is explained by magnetic flux trapping at pinning sites, inter- and intragranular currents through Josepheson junctions, and variation in microwave penetration depth with temperature and silver content. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|