SIZE EFFECT IN THE RESISTANCE OF NARROW SUPERCONDUCTING BSCCO(2212) WHISKERS NEAR THE BEREZINSKII-KOSTERLITZ-THOULESS TRANSITION

The temperature dependence of the resistance and the current-voltage c haracteristics are measured for Bi2Sr2CaCu2Ox whiskers of different wi dth, including whiskers possessing a width step. As the width decrease s, the resistivity of the whiskers below the Berezinskii-Kosterlitz-Th ouless transition temperature increases, while above the transition it decreases. This effect is explained by two-dimensional vortices leavi ng the sample through its edge and confirms the existence of vortex pa irs in layered high-T-C superconductors. (C) 1998 American Institute o f Physics.