K. Takenaka et al., INTERPLANE CHARGE-TRANSPORT IN YBA2CU3O7-Y - SPIN-GAP EFFECT ON INPLANE AND OUT-OF-PLANE RESISTIVITY, Physical review. B, Condensed matter, 50(9), 1994, pp. 6534-6537
We have investigated the anisotropic resistivities of YBa2Cu3O7-y usin
g detwinned crystals with various oxygen contents (6.68 less-than-or-e
qual-to 7 - y less-than-or-equal-to 6.93). The out-of-plane resistivit
y rho(c) shows a crossover from high-T metallic to low-T semiconductin
g behavior while the in-plane resistivity rho(a) deviates in the low-T
region from T-linear dependence. We find that the crossover in rho(c)
is linked with the onset of nonlinearity in rho(a), which seems to be
associated with the ''spin gap'' suggested by neutron and NMR studies
.