LOW-RESISTANCE ELECTRICAL CONTACTS TO SINGLE-CRYSTAL BSCCO WHISKERS

We have developed a method for preparing low-resistance contacts to single-crystal whiskers of the 2:2:1:2 phase and of mixed 2:2:1:2/2:2:2:3 phases of BSCCO, and have studied the contact resistivities over the temperature range from 50 K to 300 K. The measurement technique uses a simple three contact geometry requiring a single voltage measurement. The values of the contact resistivities obtained in this work are lower than the great majority of those previously reported for the BSCCO superconductors, making the method suitable for applications which include the nanofabrication of device structures based on micrometre-sized single crystals and single-crystal whiskers. The anomalous values of contact resistivity found in mixed phase whiskers at temperatures between the transition temperatures of the two phases is attributed to spreading resistance and anisotropy.