E-J characterization of YBa2Cu3O7-x superconducting thin films with synergetic pinning centers using AC susceptibility techniques

We report a detailed investigation of flux dynamics in YBa2Cu3O7−x (YBCO) superconducting thin films with strong synergetic pinning centers, using complex AC susceptibility measurements over a wide range of frequencies and DC magnetic fields. A new method is proposed to determine the characteristic pinning energy Uc from the electric field–current density (E–J) characteristics extracted at short time scales from AC susceptibility data. This method overcomes the limitations imposed by the use of standard Arrhenius plots, which rely on assuming a linear temperature dependence (p = 1) of the effective energy barrier (Formula presented) (Formula presented). Our results provide a more accurate approach for evaluating the magnetic field dependence of Uc, yielding a power-law dependence on the magnetic field induction (Formula presented) Uc∝Bdc−0.32, consistent with strong pinning behavior.