Bulk transport properties ofBi2Sr2CaCu2

Transport measurements have been made on ${\mathrm{Bi}}_{2}{\mathrm{Sr}}_{2}{\mathrm{CaCu}}_{2}{\mathrm{O}}_{8}$ single crystals in the Corbino disk geometry where vortices should not cross the sample edges in a fixed applied field. The results are compared directly with a strip geometry by cutting the disk into a strip and remeasuring the sample using the same contacts. Pronounced differences are observed in both the resistive transition and the current-voltage characteristics in these two geometries. The critical current density in the vortex solid phase is at least 20 times smaller than usual estimates for a strip geometry. We conclude that the transport properties of ${\mathrm{Bi}}_{2}{\mathrm{Sr}}_{2}{\mathrm{CaCu}}_{2}{\mathrm{O}}_{8}$ samples in the strip geometry are dominated by surface barriers in both solid and liquid vortex phases over a wide range of fields and temperatures.