Electrical properties of superconducting Bi-2212 thick films

Abstract

Bi2Sr2CaCu2O8+x (Bi-2212) thick films were prepared by a partial melt technique on Al2O3 and Ag substrates. Well ground Bi-2212 powder with particle size of about 1 μm was used as starting material. The films have been prepared with melting temperatures Tmelt in the range from 860 °C to 900 °C. The critical temperature Tc is determined from the temperature dependence of the film resistance, measured by a four-probe technique. The film structure and its critical current Jc are significantly influenced by the melting temperature. The maximum Jc ≅ 103 A/cm2 has been obtained on the sample prepared at Tmelt = 880-885 °C. The electrical properties of these materials are discussed by comparing the experimental data with results, calculated on the basis of the classical dirty limit model and the proximity effect model. © 2003 Elsevier Science B.V. All rights reserved.