This study investigates the effect of Al2O3–ZrO2 (AlZr) nanocomposite on the vortex dynamics and thermally activated flux flow (TAFF) properties of Bi1.6Pb0.4Sr2Ca2Cu3O10+δ high-temperature superconductor. A series of composites with varying AlZr nanocomposite concentrations (0.0–1.0 wt%) was prepared via solid-state reaction and characterized through temperature-dependent electrical resistivity measurements. The resistive transition analysis revealed that the addition of AlZr nanoparticles significantly enhances intergranular connectivity, narrows the transition width, and alters the hole carrier density across the CuO2 planes. The TAFF characteristics were analyzed via the standard Arrhenius approach and a modified TAFF model incorporating a non-linear activation energy dependence. Key parameters, including the zero-temperature activation energy (U0), critical exponent (q), and the width of the TAFF regime (ΔTTAFF), were extracted from fits to lnρ vs. 1/T, lnρ vs. T, and derivative-based plots. Optimal pinning performance was achieved at 0.3 wt% AlZr, corresponding to the highest U0 (~7.55 × 104 K) and the narrowest TAFF width (~4.0 K). Additionally, vortex-glass theory was employed to analyze the critical region below T*, yielding vortex-glass transition temperatures (Tg) and critical exponents (s) consistent with a two-dimensional (2D) vortex-glass state. The correlation between experimental data and theoretical models was validated through both indirect and direct evaluations of activation energy. These findings demonstrate that the incorporation of an optimal concentration of AlZr nanoparticles significantly enhances the flux pinning and vortex phase stability in Bi1.6Pb0.4Sr2Ca2Cu3O10+δ, offering a promising pathway to improve performance in practical high-current superconducting applications.
