Properties of superconducting, polycrystalline dysprosium-doped Bi 1.6Pb 0.5Sr 2− xDy xCa 1.1Cu 2.1O 8+ δ (0 ≤ x ≤ 0.5)

Abstract

The structural and superconducting properties of dysprosium (Dy) doped (Bi,Pb)-2212 superconductor have been studied. Dy concentration is varied from x = 0.0 to 0.5 in a general stoichiometry of Bi 1.6Pb 0.5Sr 2− x Dy x Ca 1.1Cu 2.1O 8+ δ . It is found that the Dy atoms enter into the crystal structure by replacing Sr atoms and induce significant change in lattice parameter, 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 Dy-doped samples enhance considerably at optimum doping levels. Maximum T C of 92.3 K (for x = 0.4) and J C of 1390 A/cm 2 at 64 K (for x = 0.2) are observed for doped samples as against 79.4 K and 127 A/cm 2, respectively, for the pure sample. The results are discussed on the basis of the change in hole-concentration due to Dy-doping at Sr-site of (Bi,Pb)-2212 superconductor.