1. Formation of epitaxial Tl2Ba2Ca2Cu3O10 superconducting films by dc-magnetron sputtering and triple post-annealing method.
- Author
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Wei Xie, Pei Wang, Lu Ji, De-Yong Ge, Jia-Nan Du, Xiao-Xin Gao, Xin Liu, Feng-Bin Song, Lei Hu, Xu Zhang, Ming He, and Xin-Jie Zhao
- Subjects
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THALLIUM calcium barium copper oxide films , *SUPERCONDUCTING thin films , *MAGNETRON sputtering , *ANNEALING of crystals , *CURRENT density (Electromagnetism) - Abstract
For obtaining pure phase Tl2Ba2Ca2Cu3O10 (Tl-2223) films with good superconducting properties, the growth technique is improved by dc magnetron sputtering and a triple post-annealing process. The triple post-annealing process comprises annealing twice in argon and once in oxygen at different temperatures. In the first low-temperature annealing phase in argon, Tl2Ba2CaCu2O8 (Tl-2212) is obtained to effectively minimize evaporation in the next step. With the increase of temperature in the second annealing stage in argon, the previously prepared Tl-2212 inter-phase is converted into Tl-2223 phase. An additional annealing in oxygen is also adopted to improve the properties of Tl-2223 films, each containing an optimal oxygen content value. The results of X-ray diffraction (XRD) θ–2θ scans, ω scans and rotational φ scans show that each of the Tl-2223 films has a high phase purity and an epitaxial structure. Smooth films are observed by scanning electron microscopy (SEM). The critical temperatures Tc of the films are measured to be about 120 K and the critical current densities Jc can reach 4.0 MA/cm2 at 77 K at self field. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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