  Large BSCCO crystals with electrical contacts positioned far from the edges
are studied by transport measurements, then cut into the common narrow strip
geometry, and remeasured. Instead of showing larger resistance, the narrow
strip samples display a dramatic drop in the resistance, enhanced activation
energies, and nonlinear characteristics due to strong surface barriers. The
surface barriers also dominate the resistive drop at the first-order phase
transition. Because the surface barriers are avoided in large crystals, we are
able to probe the solid phase and find good agreement with the recent
predictions of Bragg glass theory.

Superconductivity