RESIDUAL RESISTIVITY AND OXYGEN STOICHIOMETRY IN PR2-XCEXCUO4-CRYSTALS(DELTA SINGLE)

Using an improved high-temperature annealing procedure we homogeneousl y vary the oxygen content of Pr2-xCexCuO4+delta single crystals and ch ange the superconducting transition temperature in small steps. Minute changes of the oxygen concentration delta give rise to a strong incre ase of the residual resistivity but leave the Hall and the Seebeck coe fficient nearly unchanged. A strong correlation of the change of the r esidual resistivity and the change of T-c suggests that the point-defe ct scattering rate on oxygen interstitials or oxygen vacancies is an i mportant parameter determining T-c in the electron-doped high-T-c syst ems.