SUPERCONDUCTIVITY AND MAGNETISM OF THE (HG0.7BI0.3)SR-2(CA1-XPRX)CU2O6+DELTA SYSTEM

The (Hg0.7Bi0.3)Sr-2(Ca1-xPrx)Cu2O6+delta system for 1.0 greater than or equal to x greater than or equal to 0.25 has been prepared. The tra nsition temperature T-c always decreases as the rare-earth substitutio n parameter x increases. We observed the maximal T-c around x = 0.25 w ith 91 K. From the viewpoint of doping the ionic size and analytic res ults of the Pr valence in the x = 1.0 sample, we think that Pr exhibit s the trivalent state in this system. No anomalous rare-earth Pr antif erromagnetic (AFM) ordering was observed in the temperature dependence of the susceptibility down to 5 K for the Ca free sample.