CRYSTAL-STRUCTURE AND EXCESS CONDUCTIVITY OF BSCCO(2212) WHISKERS

The results of a combined study of the structural and conductive properties of BSCCO (2212) whiskers are reported. After electrical measurements the samples are examined by transmission electron microscopy, without preliminary thinning. The whiskers with transverse dimensions as small as 1 x 0.1 mu m(2) are single crystals of high quality. Some of the samples are free of dislocations. It is found that the quasi-one-dimensional behavior of the paraconductivity is independent of the presence of dislocations. However, the excess conductivity is suppressed in the twinned whiskers. The existence of a superstructure along the b-direction in a BSCCO crystal could be a possible reason for the a-b-plane paraconductivity anisotropy, resulting in the one-dimensional conducting fluctuations.