Evolution of precursor powders prepared by oxalate freeze drying towards high performance Bi-2212 wires
| Autor: | C.S. Li, Pingxiang Zhang, G.Q. Liu, X.Y. Xu, Q.B. Hao, H.L. Zheng, Lihua Jin, S.N. Zhang, G.F. Jiao |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
010302 applied physics
Fabrication Materials science Scanning electron microscope Process Chemistry and Technology 02 engineering and technology 021001 nanoscience & nanotechnology Microstructure 01 natural sciences Oxalate Surfaces Coatings and Films Electronic Optical and Magnetic Materials Freeze-drying chemistry.chemical_compound Chemical engineering chemistry Phase (matter) 0103 physical sciences Materials Chemistry Ceramics and Composites Cuprate Particle size 0210 nano-technology |
| Zdroj: | Ceramics International. 47:3299-3305 |
| ISSN: | 0272-8842 |
| DOI: | 10.1016/j.ceramint.2020.09.170 |
| Popis: | Bi2Sr2CaCu2Ox (Bi-2212) precursor powders were synthesized by the oxalate freeze drying (OFD) method. In comparison with the traditional method, the novel method could shorten the processing steps and thus improve the fabrication efficiency of precursor powder. The phase, microstructure and superconducting properties of Bi-2212 precursor powders and wires were characterized by X-ray diffraction, scanning electron microscopy and four-probe method, respectively. The thermal behavior, surface area and particle size of powders were also discussed. The results indicated that large surface area and small particle size might improve the reactivity and uniformity of powders. These properties were beneficial for the rapid and homogeneous formation of Bi-2212. High-purity crystallized Bi-2212 powders without Bi-2201 and alkaline-earth cuprates phases could be achieved. Furthermore, multi-filamentary Bi-2212 wires with OFD powders showed good microstructures without noticeable pores and large secondary particles. Therefore, high engineering critical current densities (Je) of 1619 A/mm2 and critical current densities (Jc) of 7039 A/mm2 were obtained in Bi-2212 wires at 4.2K, self field. It indicated that the oxalate freeze drying method would be a potential candidate for the mass production of high performance Bi-2212 wires. |
| Databáze: | OpenAIRE |
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