A. Odagawa et al., SUPERCONDUCTIVE PROPERTIES OF A YBA2CU3O7-DELTA SINGLE-CRYSTAL PREPARED BY CRYSTAL PULLING, Physica. C, Superconductivity, 217(1-2), 1993, pp. 222-226
We present anisotropic transport properties for a YBa2Cu3O7-delta sing
le crystal prepared by the pulling method. The resistivity in the ab-p
lane (rho(ab)), for both the as-grown sample and the oxygen-annealed s
ample, shows good metallic behavior. The resistivity just above T(c) i
s approximately 2 x 10(-5) OMEGA cm. On the other hand, the resistivit
y along the c-axis (rho(c)) changes from semiconductor-like behavior f
or the as-grown sample to metallic behavior for the oxygen-annealed sa
mple. In addition, any trace of Josephson characteristics is not obser
ved for our samples. The metallic behavior of rho(c) suggests that the
Cu-0 chain changes its conduction with hole doping, in addition to it
s role as a carrier source for the CuO2 planes.