Tunable pinning effects produced by non-uniform antidot arrays in YBCO thin films

Uniform, graded and spaced arrays of 3 μm triangular antidots in pulsed laser deposited YBa2Cu3O7 (YBCO) superconducting thin films are compared by examining the improvements in the critical current density math formula they produced. The comparison is made to establish the role of their lithographically defined (non-)uniformity and the effectiveness to control and/or enhance the critical current density. It is found that almost all types of non-uniform arrays, including graded ones enhance math formula over the broad applied magnetic field and temperature range due to the modified critical state. Whereas uniform arrays of antidots either reduce or produce no effect on math formula compared to the original (as-deposited) thin films