Synthesis, X‐ray data, and Hall effect measurements of Li‐doped Tl‐Ba‐Ca‐Cu‐O superconductor

Abstract

Lithium-doped Tl-based superconductor was prepared by adding an amount of 0.3 mol.% to the Tl 1.8 Ba 2 Ca 2.2 Cu 3 O x compound. The usual solid-state reaction method has been applied under optimum conditions. The x-ray data of the sample show a tetragonal structure with a high ratio of Tl-2223 superconducting phase. The sample showed a transition at 125 K and the zero resistance was observed at 117 K. Longitudinal (transport) and transverse (Hall) resistivities were measured at different temperatures under different magnetic fields and the data were interpreted. A positive Hall coefficient was observed at normal state and a sign reversal appears at temperatures lower than the critical temperature.

Superconducting properties of zinc substitution in Tl-2223 phase

“…Due to the difficulty to prepare a single phase of Tl-2223, the chemical substitution in this phase is still little. Kayed [13] studied the effect of Li on Tl-2223, the structure was tetragonal with high ratio of Tl-2223 superconducting phase and an offset T c of 117 K. Mohammed et al [14] examined the effect of silver on the (Tl, Pb)-2223 system. The substitution of Pb increases the superconducting transition temperature and enhances the reaction rate.…”

A Search for a Low Anisotropic Superconductor

“…Hg, Pb, Sr, Y, Pr, Co etc. ) in charge reservoir block and superconducting block [23,[27][28][29][30][31][32][33][34][35][36][37]. Parkin et al have been succeeded to prepare Tl 2 Ba 2 Ca 2 Cu 3 O x superconductor with critical temperature, which varies from 118 to 127K depending upon the synthesis conditions [8].…”

“…Figure 4 shows the results of T c (0) and R(300K) for different Ag 2 O doping concentrations. The doping of Li in Tl-2223 starting composition results in a critical temperature of 117K and the normal state resistivity becomes independent of the applied magnetic fields [29]. Since the maximum T c (0) in a given compound also strongly depends on the interlayer coupling so the external pressure can be used as a source to improve the superconducting properties intrinsically.…”

Synthesis and characterization of antimony-doped Bi-based superconducting materials

“…Pb doping in Bi-Sr-Ca-Cu-O and Tl-Sr-Ca-Cu-O superconducting systems induces a partially melted liquid phase that eases the diffusion of elements to form the high-Tc phases and increases their critical current density [1]. Since superconductivity in Bibased systems is believed to be associated with the Cu-O 2 planes, most of the substitutions have been made at Cu sites [2][3][4].…”