Effect of surface barriers on transport properties of Bi2Sr2CaCu2O8 singlecrystals using the Corbino disc configuration

Transport measurements have been made on Bi2Sr2CaCu2O8 single crystals in b oth Corbino disc and strip geometries. Pronounced differences are observed in both the resistive transition and the current-voltage characteristics in these two geometries. Surface barriers affect the behaviour of the strip a nd reduce the measured resistance of the vortex liquid by over two orders o f magnitude with respect to the Corbino geometry. The critical current dens ity of the Corbino disc, which reflects the true bulk critical current, is a factor of at least 20 times smaller. We conclude that the transport prope rties of Bi2Sr2CaCu2O8 samples in the strip geometry are dominated by SE in both the solid and liquid vortex phases over a wide range of fields and te mperatures.