Growth of high performance single grain Y-Ba-Cu-O Bulk superconductor with sol-gel derived Y2Ba4CuAgO addition

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(1)Growth of high performance single grain Y-Ba-Cu-O bulk superconductor with sol-gel derived Y2Ba4CuAgOy addition Po-Wei Chen1, Chien-Ju Liu1, Shih-Yun Chen2, In-Gann Chen1* and Maw- Kuen Wu3 1. Department of Materials Science and Engineering, National Cheng Kung University, Tainan, Taiwan 2. Department of Materials Science and Engineering, National Taiwan University of Science and Technology, Taipei, Taiwan 3. Institute of Physics, Academia Sinica, Taipei, Taiwan Presenting author:poway0703@gmail.com * Correspondence: ingann@mail.ncku.edu.tw. This study investigates the superconductivity of single grain Y-Ba-Cu-O (YBCO) bulk superconductors with the addition of nano-scale second phases of Y2Ba4CuAgOy (Y2411(Ag)). The sol-gel process was utilized to fabricated fine and uniform Y2411(Ag) particles.[1] With different amounts of Y2411(Ag) addition, at first, the Tc of these composites remains approximately constant at 90 ± 1 K and narrow width of T implies no substitution interactions occur between YBa2Cu3O7− (Y123) matrix and Y2411(Ag) phase during melting process. On the other hand, with the addition of Y2411(Ag), Jc reaches 5.8 x104 A cm-2 at 77K. This is almost 3 times higher than that of the un-doped sample (~1.9 x104A cm-2). Notably, the value of the maximum trapped field (Bt,max) increases linearly with the amounts of Y2411(Ag) addition. YBCO bulk with 4 mol % Y2411(Ag) addition, Bt,max was enhanced to 0.2 Tesla, which is 2.5 times higher than that of YBCO samples without Y2411(Ag) addition. Microstructure analysis demonstrates that Y2411(Ag) particles result in nano-scale (10-20nm) inclusions and distributed homogeneously in the Y123matrix after melt-growth process. The enhancing of superconductivity was attributed to the improvement in microstructure after Y2411(Ag) addition.. Figure 1: Bt,max as a function of Y2411(Ag) phase content in the superconducting nanocomposite. For comparison, the Bt,max of Y123/Y211 and Y123/Y211/CeO2 were included in this figure.. Reference [1] P. W. Chen, C. J. Liu, S. Y. Chen, Y. T. Nien, and I. G. Chen, IEEE Trans. Appl. Supercond. 21, 2710 (2011).

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