Signature of T$_\textrm{c}$ above 111 K in Li-doped (Bi,Pb)-2223 superconductors: synergistic nature of hole concentration, coherence length and Josephson interlayer coupling

N. K. Man; Huu T. Do

doi:10.1103/PhysRevMaterials.8.124802

paper

Signature of T $_{c}$ above 111 K in Li-doped (Bi,Pb)-2223 superconductors: synergistic nature of hole concentration, coherence length and Josephson interlayer coupling

arXiv:2405.04689 · doi:10.1103/PhysRevMaterials.8.124802

Abstract

Understanding the bottleneck to drive higher critical transition temperature $T_{c}$ plays a pivotal role in the underlying study of superconductors. We systematically investigate the effect of Li $^{+}$ substitution for Cu $^{2 +}$ cations on the $T_{c}$ , hole concentration, coherence length and interlayer coupling, and microstructure in Li-doped Bi $_{1.6}$ Pb $_{0.4}$ Sr $_{2}$ Ca $_{2}$ Cu $_{3}$ O $_{10 + δ}$ or (Bi,Pb)-2223 compound. Remarkably, we demonstrate by utilizing a long-time sintering accompanied by a multiple recurrent intermediate stages of calcining and pressing within our renovated solid-state reaction method, the optimal Li-doped (Bi,Pb)-2223 samples achieve the well-enhanced $T_{c}$ of 111--113.8 K compared with the standard value of 110 K. We evince the superconducting mechanism that the substitution of Li $^{+}$ for Cu $^{2 +}$ ions on the CuO $_{2}$ layers causes augmenting the hole concentrations and promotes the correlation between the overdoped outer and the underdoped inner CuO $_{2}$ planes, and thus effects improve $T_{c}$ . Following a universal quadratic relation between $T_{c}$ and hole concentration, a new higher optimal hole concentration is provided. Additionally, by analyzing the Aslamazov-Larkin and Lawrence-Doniach theories on the reliable excess conductivity data near the critical temperature, we observe the strong effect of Li-doping on the system. The coherence length steadily increases versus the Li-doped content, while the Josephson interlayer coupling strength between the CuO $_{2}$ layers almost remains a constant for the whole series of Li-doping. Our findings establish an insightful roadmap to improve the critical temperature and intrinsic superconducting properties in the Bi-2223 compounds through the doping process.

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Fingerprint of $T_{c}$ advancement in Li-doped Bi-2223 superconductors prepared by cationic molecular mixing within Pechini sol-gel synthesis

Signature of Tc​ above 111 K in Li-doped (Bi,Pb)-2223 superconductors: synergistic nature of hole concentration, coherence length and Josephson interlayer coupling

Abstract

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Cited by in corpus (1)

Signature of T $_{c}$ above 111 K in Li-doped (Bi,Pb)-2223 superconductors: synergistic nature of hole concentration, coherence length and Josephson interlayer coupling