C-AXIS RESISTANCE PEAK ABOVE THE CRITICAL-TEMPERATURE IN LAYERED SUPERCONDUCTORS

The possibility fully describing the behavior of transverse resistivit y rho(c) in cuprate superconductors exclusively in terms of some recen tly proposed normal-state models is discussed. It is shown that these models do not give a completely satisfactory description of the appare nt singularity in rho(c) at the critical temperature in Bi2Sr2CaCu2O8x, and that they fail to describe data concerning a lower-T-c cuprate superconductor as Bi2Sr2CuO6+x (T-c congruent to 15 K). It is argued t hat these difficulties cannot be overcome considering the normal-state contribution to rho(c) only. The role of the density of states fluctu ations in the behavior of rho(c) just about the transition temperature is recalled. It is shown that, laking into account this contribution, it is possible to dramatically simplify the description of the the no rmal-state transverse resistivity, This can give important hints for t he understanding of the transverse electrical transport properties of these materials.