Superconducting transport properties of Bi2Sr2CaCu2O8+x bicrystal grain boundary junctions

Abstract

We have performed a detailed study of the superconducting transport properties of Bi2Sr2CaCu2O8+x bicrystal grain boundary junctions (GBJs). The GBJs were fabricated by the deposition of c-axis oriented epitaxial Bi2Sr2CaCu2O8+x films on SrTiO3 bicrystal substrates. The measured resistive transition R(T), the current-voltage characteristics (IVCs), the temperature dependence of the critical current density Jc(T), and the magnetic field dependence of the critical current Ic(B) of the Bi2Sr2CaCu2O8+x GBJs are similar to those observed for YBa2Cu3O7−δ GBJs. However, for the same misorientation angle the magnitude of Jc is almost an order of magnitude smaller for the BSCCO-GBJs. The R(T) dependencies and the IVCs of the BSCCO-GBJs are close to the prediction of the resistively shunted junction (RSJ) model. The Ic(B) dependencies are close to those of large Josephson junctions with overlap geometry. Our results show that BSCCO-GBJs may be useful for cryoelectronic applications.