Role of Columnar Defect Size in Angular Dependent Flux Pinning Properties of YBCO Thin Films

The effect of artificially produced BaHfO3, BaZrO3, and BaSnO3 nanocolumns within the YBa2Cu3O6+x (YBCO) lattice is investigated in terms of flux pinning and vortex dynamics by studying the properties of the angular dependent critical current density. Based on the differences in the growth mechanisms of discussed dopant species, the superconducting properties such as the critical current density, the accommodation field, and the effective pinning force have been observed to be greatly dependent on the size and the distribution of the nanocolumns. Therefore, the mechanisms of the collective individual and multivortex pinning have been observed being in a critical role when interpreting the in-field critical current anisotropy in YBCO films with artificial pinning centers.