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.
The world’s record in super-current density at 65K, & 90.2K, which was obtained in the JSPS Project No. 19510125