Increasing the Pinning Force and Critical Currents in YBaCuO-type Superconductors

In this work, we conducted a detailed analysis of the types of mechanisms by which vortex lines interact with pinning centers generated in \(\mathrm {YBa}_2\mathrm {Cu}_3\mathrm {O}_{7-d}\) (Y123) single crystals by annealing in high oxygen pressure and Mo-substitution. Our analysis is based on the properties of these centers influencing the pinning force. Based on the previously obtained results on the dependence of the critical current density, \(j_{\mathrm {c}}\), on the magnetic field, \(j_{\mathrm {c}}(H)\), we determined \(j_{\mathrm {c}}\) as a function of temperature, \(j_{\mathrm {c}}(T)\), for different \(H\), which we used to answer the question of which pinning mechanism, \(\delta l\) or \(\delta T_{\mathrm {c}}\), dominates in Y123 single crystals. Our results differ both quantitatively and qualitatively from those previously reported, which we explain by understanding the types of pinning centers generated in studied materials. Our results provide a better understanding of the phenomena leading to significant increases in critical currents in Y123 and thus allow for better prediction of pinning centers that operate effectively under desired magnetic fields and temperatures. Published by the Jagiellonian University 2026 authors