Highly enhanced superconducting properties of Eu-doped (Bi,Pb)-2212

Abstract

The structural and superconducting properties of Eu-doped (Bi,Pb)-2212 superconductor have been studied. Eu concentration is varied from x=0.0 to 0.4 in a general stoichiometry of Bi1.6Pb0.5Sr2-xEuxCa1.1Cu2.1Oy. It is found that the Eu atoms enter into the crystal structure by replacing Sr atoms and induce significant changes in lattice parameters, microstructure, hole-concentration and normal-state conductivity of the system. The critical temperature (T-C) and critical current density (J(C)) at self-field of the Eu-doped samples enhanced considerably for optimum doping levels. Maximum TC-onset of 95.7 K (for x=0.2) and J(C) of 1196 A/cm(2) at 64 K (for x=0.1) were observed for doped samples as against 79.8 K and 105 A/cm(2), respectively, for the pure sample. The results are discussed on the basis of the changes in hole-concentration due to Eu-doping.