SYSTEMATICS OF THE ELECTRONIC TRANSPORT-PROPERTIES IN THE METALLIC STATE OF PR2-XCEXCUO4-CRYSTALS(DELTA SINGLE)

Using an improved high temperature reduction method we found that in t he n-type high-T-c-system Pr2-xCexCuO4+delta bulk superconductivity ca ll be established between x less than or equal to 0.09 and x approxima te to 0.17 i.e. over a much broader range than previously reported. Th e T-2-contribution to the resistivity increases with the Ce-concentrat ion. Is the evolution of the Hall-coefficient with the Ce-concentratio n we find clear indications for a coexisting hole-type and electron-ty pe of orbit at the Fermi surface.