Effect of Partial Replacement of Mercury by Lead on Structural and Electrical Properties ofHg1-xPbxBa2CaCu2O6+δ Superconductor

Abstract

The physical properties of the Hg_1-xPb_xBa₂CaCu₂O_6+δ superconductors at x values of 0, 0.05, 0.1 and 0.2 were examined to the simultaneous partial substitution of lead (Pb) at the mercury site. The capsule's samples were prepared in three steps by solid-state reaction. All samples had tetragonal structure with two phases: a main phase of High-Tc Hg-1212 and a secondary phase of Low-Tc Hg-1201, as revealed by structural analysis. In addition, there were impurity phases like CaHgO₂ and CuO. The lattice parameter, P(Hole) concentration, and c/a values changed when the lead (Pb) concentration in the prepared Hg_1-xPb_xBa₂CaCu₂O_6+δ compound was increased from 0 to 0.2. The zero critical transition temperature for HgBa₂CaCu₂O_6+δ, Hg_0.95Pb_0.05Ba₂CaCu₂O_6+δ, Hg_0.9Pb_0.1Ba₂CaCu₂O_6+δ and Hg_0.8Pb_0.2Ba₂CaCu₂O_6+δ, were found to be 82, 86, 93 and 106 K, respectively, while the onset critical transition temperature was found to be 101, 103, 105 and 124 K respectively.