Synthesis of YBa2Cu3O7鈭捨?/sub> and Y2BaCuO5 Nanocrystalline Powders for YBCO Superconductors Using Carbon Nanotube Templates
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- 作者：Yunhua Shi ; Tawfique Hasan ; Nadendla H. Babu ; Felice Torrisi ; Silvia Milana ; Andrea C. Ferrari ; David A. Cardwell
- 刊名：ACS Nano
- 出版年：2012
- 出版时间：June 26, 2012
- 年：2012
- 卷：6
- 期：6
- 页码：5395-5403
- 全文大小：1140K
- 年卷期：v.6,no.6(June 26, 2012)
- ISSN：1936-086X
文摘
We fabricate nanosized superconducting YBa2Cu3O7鈭捨?/sub> (Y-123) and nonsuperconducting Y2BaCuO5 (Y-211) powders using carbon nanotubes as template. The mean particle size of Y-123 and Y-211 is 12 and 30 nm, respectively. The superconducting transition temperature of the Y-123 nanopowder is 90.9 K, similar to that of commercial, micrometer-scale powders fabricated by conventional processing. The elimination of carbon and the formation of a high purity superconducting phase both on the micro- and macroscale is confirmed by Raman spectroscopy and X-ray diffraction. We also demonstrate improvement in the superconducting properties of YBCO single grain bulk samples fabricated using the nanosize Y-211 powder, both in terms of trapped field and critical current density. The former reaches 553 mT at 77 K, with a 20% improvement compared to samples fabricated from commercial powders. Thus, our processing method is an effective source of pinning centers in single grain superconductors.