Effect of Li₂O on the microstructure, magnetic and transport properties of Tl-2223 superconductor

The presentation will provide an account of the effect of Li₂O on the ease of phase formation and superconducting properties of Tl₂Ba₂Ca₂Cu₂O_10+δ (Tl-2223) material. Li substitution only slightly decreases the superconducting transition temperature, while the optimal concentration of 20% doping improves the critical current density (J_c) by ~ two fold. We found substantial effects on the synthesis temperature, microstructure and normal state transport properties of Tl-2223 with Li₂O addition. Short-time thermal annealing under flowing Ar+4%H₂ (1 hr.) further improves the superconducting volume fractions, as well as J_c.