New method of synthesis and physical properties of thick superconducting Er-123 films

作者：Muralidhar M^*; Sakai N; Machi T; Miyajiri T; Hirabayashi I; Tanaka S

来源：Physica C-Superconductivity and Its Applications, 2008, 468(15-20): 1345-1349.

DOI：10.1016/j.physc.2008.05.055

• Er2BaO4
• thick films
• XRD
• SEM
• critical current density (J(c)) and I-c
• LRE-Ba2Cu3Oy

We have developed a low-cost, short time manufacturing process using a novel method, starting from a mixture of Er2BaO4, BaCuO2, and CuO, with an excess of Er at expense of Ba. Several micrometers thick films were prepared by the screen-printing technique, spreading the mixture paste on silver substrates, processed then in Ar-1% O-2 atmosphere. Using a double-step annealing process, we obtained good quality Er-123 thick films on silver substrates, with T-c (onset) 92 K. Formation of large flat grains was observed by scanning electron microscope. According to XRD analysis, the films were preferentially c-axis oriented. The magnetic (induced), self-field J(c) measured at 77 K was above 32 kA/cm(2). We observed a strong dependence of the transport current, I-c, on the grain size. The maximum h at 77 K as high as 10 A was observed in the sample with the average grain size around 40 mu m. The present results indicate that our technology, enabling preparation of large-area superconducting thick films on Ag-based substrates in short processing times, is relatively cheap and appropriate for utilization in long-length RE-123 silver sheath wire production for commercial applications.

• 出版日期2008-9-15