TRANSPORT AND MAGNETIC-PROPERTIES OF TL2BA2CUO6+DELTA SHOWING A DELTA-DEPENDENT GRADUAL TRANSITION FROM AN 85-K SUPERCONDUCTOR TO A NONSUPERCONDUCTING METAL

Transport and magnetic properties are investigated for Tl2Ba2CuO6+delta, which shows a gradual transition from an 85-K superconductor to a nonsuperconducting normal metal, as the excess oxygen content delta is increased from approximately 0 to approximately 0.1. Hall measurements demonstrate that this transition arises from an overdoping of the hole carriers by excess oxygen. The temperature dependence of the resistivity is well fitted to a power-law dependence for all delta's, while the exponent shows a systematic change from linear (delta approximately 0) to quadratic (delta approximately 0.1) dependence. No significant changes of the Hall coefficient nor spin susceptibility are observed at the superconductor-metal phase boundary, suggesting a similarity and continuity between both the electronic structures. This is in shape contrast to the previous observations for La2-(x)Sr(x)CuO4.