FLUX-PINNING IN I0.9PB0.13)(2)SR-2(CA(0.98)R(0.02))(2)CU3O10+DELTA SYSTEM (R=SM, EU, GD, DY, CA)

The (Bi0.9Pb0.15)(2)S(r)2(Ca(0.95)R(0.02))(2)Cu-3 O-10+delta supercond uctors (R = Sm, Eu, Gd, Dy, Ca) were prepared and the flux pinning eff ects of all samples were studied using vibrating sample magnetometer. We found that the pinning potential energy U increases but the flux pi nning force F-p decreases when the magnetic moment of the rare earth e lement increases. We believe that this effect may come from the area o f normal state resulting from the magnetic moment of the rare earth el ement which was particularly substituted for the Ca2+ ion of our sampl es.