The properties of co‐sputtered YBa2Cu3O7and CeO2thin films
| Autor: | L. H. Allen, E. J. Cukauskas |
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| Rok vydání: | 1996 |
| Předmět: | |
| Zdroj: | Journal of Applied Physics. 80:5843-5849 |
| ISSN: | 1089-7550 0021-8979 |
| DOI: | 10.1063/1.363577 |
| Popis: | We have investigated the morphology and superconducting properties of off‐axis co‐sputtered thin films of YBa2Cu3O7 and CeO2. The composite films were made with CeO2 concentrations up to approximately 43%. Morphology investigations using x‐ray diffraction and scanning electron microscopy suggest that films with less than 29% CeO2 may consist of a distorted YBCO crystal structure with Ce being incorporated into the lattice. Films with more than 29% consist of a new material phase. T c and resistance ratio decreased with increasing CeO2 concentration. Degradation of T c after photoresist processing was observed for films with higher amounts of CeO2. However, this degradation was reversed and T c improved beyond that of the as‐deposited film by processing the films with an oxygen plasma etch. The temperature dependence of the critical current near T c showed two power law dependence regions with a crossover near 0.99 T c for films having low concentrations of CeO2. This crossover shifted to lower temperatures for films with higher amounts of CeO2. I c ’s were decreased by small applied magnetic fields, and for some samples response was observed which was greater than 0.5 mA/G and increased with decreasing temperature. For a sample having 26% CeO2, a 40% reduction in critical current for a 2 G applied field was observed. These magnetic field responses indicate that this material may be a promising candidate for the development of Josephson vortex flow devices. |
| Databáze: | OpenAIRE |
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