The influence of zinc on Tl-1223 superconductors

Superconducting properties of zinc substitution in Tl-2223 phase

“…We feel that the Zn prefer to replace in Cu-site rather than Tl-site, the ionic radius of Tl 3+ (coordination number 6: 102pm). Theses results are similar to those reported by Kühberger and Gritzner [7] in the (Tl 0.5 Pb 0.5 )(Sr 0.9 Ba 0.1 ) 2 Ca 2 (Cu 1−x Zn x ) 3 O 8+δ system. The second reason may be due to the chemical properties of zinc.…”

“…This is because the Zn substitution reduced the formation of Tl-1212 phase and enhanced the formation of Tl-1223, prepared by solid-state reaction. The substitution of Zn in the Cu-site of (Tl 0.5 Pb 0.5 )(Sr 0.9 Ba 0.1 ) 2 Ca 2 Cu 3 O 9 phase was reported by Kühberger and Gritzner [7], showing a suppression in the superconducting transition temperature and critical current density as Zn-content increased. On the other hand, partial replacement of copper by zinc in Y-123 gradually depressed the superconducting transition temperature [8].…”

“…This reduction in oxygen-content may convert the un-substituted sample from optimum doping to under-doped region, where suppression in T c is observed. However, it is found that the thallium based 1223 and 2223 superconductors accept such a large amount of Zn without any dramatic deterioration in the superconducting properties [7]. These results are in contrary with those obtained by Xu et al [19], in the YBa 2 (Cu 1−x Zn x ) 3 O 7−δ system.…”

A Search for a Low Anisotropic Superconductor

“…The increase in T c (0) was attributed to the improved coupling between the CuO 2 planes due to the decreased c-axis length [100]. The critical temperature and the critical current density of Tl-1223 superconductor decreases with low level doping concentration of 3d transition metals Co, Zn, Fe and Ni at Cu site and superconductivity disappears for higher concentrations of these elements [101][102][103][104]. The presence of these ions in CuO 2 planes acts as scattering centers, which resulted in the Cooper pair breaking, and destroys the superconducting state in Tl-1223 compounds.…”

Suppression of Tc in Co-doped (Cu0.5Tl0.5)Ba2Ca2Cu3−xCoxO10−δ superconductor

“…The carriers in CuO 2 planes can be perturbed by directly doping at the planner sites. Many research groups working in the field of high T c superconductivity focus their attention on the CuO 2 planes; they substitute different elements such as Co, Ni, Fe and Zn at Cu sites in CuO 2 planes in order to study the response of the superconductor material to a disorder created by these ions in CuO 2 planes [6][7][8][9][10][11][12][13][14]. In these studies, it was found that doping of such impurities leads to a decrease in the critical temperature "T c ".…”