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

Bi2.1Sr1.96CaxCu2.0Ox (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, Rc 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/cm(2) (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. (C) 2012 Published by Elsevier B.V. Selection and/or peer-review under responsibility of the Guest Editors.