Heat Treatment Effect on the Metal Contact of High-Tc(Pb, Bi)SrCaCuO Superconductor

Better metal electrode can be obtained by heat treatment which causes deeper diffusion of metal particles into the (Pb, Bi)SrCaCuO superconductor to improve contacts between metal electrodes and the sample. However, high- T c phase of the specimen was destroyed at 700°C and the sample showed semiconducting behaviour. Low room temperature contact resistivity was obtained about 3.21×10 -4 (Ω-cm 2 ) and 2.34×10 -6 (Ω-cm 2 ) at 77 K for a sample with evaporating silver electrodes and annealed at 600°C for 2 hours. Non-ohmic contacts are observed for the indium and aluminum terminals.