Influence of As2O3 vapor pressure on phase formation and superconducting properties of Tl-2212 HTS
Journal
Low Temperature Physics
Date Issued
January 1, 2026
DOI
10.1063/10.0042171
Abstract
As-substituted Tl<inf>2–x </inf>As<inf>x</inf>Ba<inf>2</inf>CaCu<inf>2</inf>O<inf>8+δ</inf> (Tl-2212) high-temperature superconductor was synthesized using a two-step method. In the first step, the Ba<inf>2</inf>CaCu<inf>2</inf>O<inf>y</inf> multiphase precursor was prepared via the in situ polymerization method, and in the second step, Tl and As were simultaneously introduced as dopants (x=0.5–2.0wt%). The final synthetic step was carried out in a closed quartz tube under an oxygen pressure of 2 atm. The non-substituted sample showed an onset superconducting transition temperature, T<inf>c</inf><inf>(onset)</inf>, of 107K. The sample doped with 1.5wt% As showed the highest T<inf>c</inf><inf>(onset)</inf> ≈ 114.5K. However, further substitution with 2.0wt% As led to a decrease in the transition temperature. Notably, the sample dope with 0.5wt% As displayed a significant enhancement in intergranular critical current densities, surpassing those of the As-free sample. Overall, the results showed that moderate doping with arsenic trioxide (As<inf>2</inf>O<inf>3</inf>, x=0.5–1.5wt%) enhances the onset critical superconducting transition temperature, while higher doping levels (1.0–2.0wt%) adversely affect the intergranular critical current density.