Multi-Criteria Evaluation of Dy-Substituted Bi-2212 Ceramics: Structural, Electrical, and Superconducting Enhancements

This study investigates the synthesis–structure–property relationships in functional electronic materials by coupling structural evolution with electrical and superconducting performance. On this basis, the role of Dy ³⁺ substitution (0.00 ≤ x ≤ 0.10) on the structural, flux pinning ability, electrical, and superconducting characteristics of Bi _2.1−x Dy _x Sr _2.0 Ca _1.1 Cu _2.0 O _y (Bi-2212) ceramics, synthesized via the conventional solid-state reaction method, is systematically examined. X-ray diffraction (XRD), electrical resistivity (ρ–T), bulk density, and current–voltage (I–V) measurements reveal that an optimum substitution level of x = 0.01 yields superior performance. At this composition, microstructural refinement enhances grain connectivity, lattice coherence, crystallinity, and nucleation-pinning centers, leading to improved superconducting transitions (onset superconductive temperatures ≈ 85.0 K and offset ≈ 80.3 K), larger crystallite size, and enhanced texture quality. Increased carrier concentration and stabilized Bi-O and Cu-O planes promote electron-phonon interactions, supporting stronger superconducting cluster formation. Correspondingly, the critical current density reaches a maximum of 67 A/cm ² , attributed to reinforced flux pinning and vortex coupling. Multi-criteria decision analysis (MCDA) further confirms the optimized sample (Bi _2.09 Dy _0.01 Sr _2.0 Ca _1.1 Cu _2.0 O _y ) achieves the highest normalized performance score (~ 0.90), demonstrating that Dy substitution at x = 0.01 simultaneously improves structural integrity, electrical conductivity, and superconducting efficiency. These results establish Dy doping as a viable pathway to enhance the functional reliability of Bi-2212 ceramics, advancing their potential for electronic and energy-related applications.