TRANSPORT-PROPERTIES OF SEVERAL SERIES OF HIGH-TC OXIDES

The main results of transport studies on several series of high T(c) oxides in the normal state are reported. The resistivity of YBa2(Cu1-xZnx)3O7 alloys obeys Matthiessen's rule. Oxygen depletion of YBa2Cu3O7(YBCO) or doping with Co or Fe decouples the CuO2 planes and enhances superconducting fluctuations above T(c). For three materials there is a change in sign in the thermoelectric power (TEP) near to the hole concentration corresponding to maximum T(c). The TEP curves of four of the more anisotropic high T(c) oxides are remarkably similar and therefore are characteristic of weakly coupled CuO2 layers in the superconducting region. For oxygen depleted YBCO and the related TlPb septenary compound the Hall number decreases strongly with doping while for YBCO the Hall conductivity initially shows a much weaker variation.