Electrical and magnetic properties of bulk (Bi1.6Pb0.4) (Sr1.8Ba0,2) (Ca1-xErx)2Cu3Oy superconducting system

The effects of partial substitution of Ca by Er on the superconductivity and normal state properties of the bulk superconductor (Bi1.6Pb0.4)(Sr1.8Ba0.2)(Ca1-xErx)(2)Cu-3 Oy (0 less than or equal to x less than or equal to 0.2) have been investigated using electrical resistivity, a.c. and d.c. magnetic susceptibility measurements. Above the excess conductivity region, all samples are characterised by a linear temperature dependence of the electrical resistivity. The analysis of the resistivity data in the normal state reveal that the residual resistivity and the parameter p (related to the percolation path in granular samples) increase with increasing x. The critical transition temperature determined from resistivity data, T-c and T-c(p = 0), are identical to intraand intergrain critical temperatures derived from the a.c. susceptibility measurements. These temperatures decreases linearly with increasing Er content. For samples with x less than or equal to 0.005 a temperature independent susceptibility was evidenced and for x > 0.005 the susceptibility data as a function of temperature is well described by a Curie-Weiss law with an effective magnetic moment corresponding to the Er3+ ion.