Preparation and Physical Properties of (Bi1-xLnx)2.2Sr1.8CaCu2Oy (Ln=La, Pr and Nd, x≦0.25)

Abstract
Solid solutions (Bi1-x Ln x )2.2Sr1.8CaCu2O y (Ln=La, Pr and Nd, x≦0.25) were prepared. Of these three Ln ions replacing Bi3+, Pr was not trivalent, the average valence of Pr being shown to be 3.5. With increase of x, the onset of superconducting transition temperature and hole concentration initially increase, then decrease steadily with increase of x equally for all the three series, irrespective of difference in lanthanide elements substituted.