Enhanced Flux Pinning in MOD-derived YBCO Films Through Hybrid 1D-3D Landscapes of Irradiated Columnar Defects and Pre-formed Nanocrystals

Hybrid pinning landscape combining one-dimensional (1D) and three-dimensional (3D) defects is regarded as the best solution for enhancing in-field critical current densities Jc of YBCO (YBa2Cu3O7-x). Nevertheless, the interplay between different defects remains unclear. In this work, the effects of hybrid pinning centers containing 3D BaHfO3 nanoparticles (NPs) and irradiation-induced 1D columnar defects (CDs) on YBCO were studied. Irradiation (200 MeV Xe ions, 2e10 ions/cm2) enhanced Jc(77 K, 5 T) by 8.6 times. Interestingly, the temperature dependence of normalized Jc is totally different under different magnetic fields. At low field, the pinning effect of NPs is dominant, while CDs promote vortex creep. Subsequently, contribution of CDs gradually increases with increasing magnetic field, with NPs providing supplemental pinning that suppresses vortex kink expansion between CDs. These findings provide a mechanistic understanding of the dynamic transition within hybrid pinning systems and establish a controllable route for optimizing YBCO performance for large-scale applications.