Development of the technology for RE-123 superconducting films using RE-210

We developed a novel technology, using a mixture of Er2BaO4, BaCuO2, and CuO, with an excess of Er at expense of Ba. Several micrometers thick films were prepared by screen-printing technique, spreading the mixture paste on silver substrates, processed then in Ar-1% pO2 atmosphere. Using a double-step annealing, good quality Er-123 thick films were grown on silver substrates, with Tc onset 92 K. SEM and TEM analyses confirmed formation of large flat grains, XRD analysis showed a preferential c-axis orientation. The magnetic self-field Jc at 77 K was above 50 kA/cm2. A strong dependence of the transport current, Ic, on the grain size was observed. The technology enables preparation of large-area thick superconducting films in a short processing time, is relatively cheap and appropriate for utilization in long-length RE-123 silver sheath wire production for commercial applications. These results led to two new Japanese patents.

Importance of newly developed process and formation of plate like crystals on commercial silver substrate. Note that highly oriented films on commercial silver substrates, this is the old dream of the scientists, which was discovered by the solid phase (RE-210) and liquid phase (Ba-Cu-O) reaction process.

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