Effect of Partial Melting Parameters on the Microstructures and Critical Current Density of Bi-2212 Thick Films

Bi2.1Sr1.96Ca x Cu2.0Ox (Bi-2212) thick films with Ag substrates were prepared through dip coating process. By X-ray diffraction (XRD) and scanning electron microscopy (SEM) characterizations, the influences of heat treatment parameters on the phase transition process and the aligned growth of Bi-2212 grains have been systematically studied. The maximum heat treatment temperature, T max, and cooling rate, R c has been optimized. Meanwhile, the influences of the coating density on the microstructures and the transport properties have also been discussed by applying an additional cold pressing. The J c value of over 7300 A/cm2 (77 K, self field) has been obtained from the direct powder pressing process, which is over 60% higher than that from the traditional dip coating thick film.