In this paper we have reported investigations on the effect of simultaneous substitution of Bi and Tl at the H𝑔 site in the oxygen deficient H𝑔O𝛿 layer of H𝑔Ba2Ca2Cu3O8+𝛿 cuprate superconductor. Bulk polycrystalline samples have been prepared by the two-step solid state reaction process (precursor route). It has been observed that the as grown H𝑔Bi0.2–𝑥Tl𝑥Ba2Ca2Cu3O8+𝛿 (with 𝑥 = 0.00, 0.05, 0.10, 0.15, 0.20) corresponds to the 1223 phase. It has been found that the 𝑇c varies with the average cationic size $\langle R_d \rangle$ of the dopantcations. The optimum 𝑇c of ∼ 131 K has been found for the composition H𝑔Bi0.15Tl0.05Ba2Ca2Cu3O8+𝛿. This composition leads to the average dopant cation size of ∼ 1.108 Å which is very close to the size of H𝑔2+ (∼ 1.11 Å). The microstructure for H𝑔Bi0.15Tl0.05Ba2Ca2Cu3O8+𝛿 has been found to be most dense and this phase exhibits the highest stability. The 𝐽c of the optimum material H𝑔Bi0.15Tl0.05Ba2Ca2Cu3O8+𝛿 is found to be ∼ 1.29 × 103 A/cm2 at 77 K.
Volume 44, 2021
Continuous Article Publishing mode
Prof. Subi Jacob George — Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bengaluru
Chemical Sciences 2020
Prof. Surajit Dhara — School of Physics, University of Hyderabad, Hyderabad
Physical Sciences 2020
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