Substitution and doping of YBa2Cu3O7 by Agn+, Sr2+Sc3+ and related properties

We investigated two series of samples of YBa2Cu3-zSczO7-delta prepared at t he sintering temperature 967 and 980 degreesC and the two series of YBa2-yS rYCu3O7-delta-Ag2O systems differing in silver doping with 2 and 10 wt% Ag2 O by X-ray diffraction, resistive and detailed magnetization measurements. Doping levels of Sc, Sr and Ag2O range from z=0 to 1.0, y=0.0 to 1.0 and Ag 2O (2 and 10 wt%), respectively. For all doping levels y, z and silver oxid e the superconducting phases at 77.3 K were observed. For the higher Sc con tent z, a deterioration of the critical temperature (T-c), the density, the volume fraction of superconducting phase, as well as the volume magnetizat ion (magnitude) M, the volume magnetic susceptibility, the first magnetic p enetration field (H-p1) and the slope of magnetization loops of the samples were observed in relation to sintering temperature. Increasing Sr content results in gradual decreasing of superconducting properties: T-c, H-p1, and M, the slope of magnetization loops and magnetization hysteresis, they all decrease with increasing Sr content at higher Sr levels. (C) 2001 Publishe d by Elsevier Science Ltd.