ELECTRICAL-RESISTIVITY STUDY OF METALLIC PR2-XCEXCUO4-CRYSTALS OVER ABROAD CONCENTRATION AND TEMPERATURE-RANGE(DELTA SINGLE)

We report electrical resistivity measurements on single crystals of th e electron doped high-T-c superconductor Pr2-xCexCuO4+delta which have been made metallic in the concentration range 0.04 < x < 0.18 using a newly developed high temperature reduction technique. At low Ce-conce ntrations 0 < x < 0.04 we find indications of a thermally driven phase separation transition at high temperatures. For higher Ce-concentrati ons the temperature dependence of the resistivity below room temperatu re changes continuously from approximately linear in T towards a non-u niversal power law with increasing Ce-concentration. At high temperatu res we always observe a cross-over to a linear temperature dependence. Measurements of the resistivity on single crystals with substitutions of Ni on the Cu-position revealed a change of the elastic as well as the inelastic scattering rate. The systematic development of the resis tivity with changing charge carrier concentration in Pr2-xCexCuO4+delt a is compared to that known for the hole doped high-T-c system La2-xSr xCuO4+delta. (C) 1997 Elsevier Science B.V.