Large Jc enhancement by ion irradiation for thick YBa2Cu3O7−δ films prepared by photoassisted metalorganic chemical vapor deposition

Abstract
Thick superconducting films of YBa2Cu3O7−δ grown by photoassisted metalorganic chemical vapor deposition that have shown a decrease of Jc with increasing thickness (>1 μm) have been exposed to ion irradiation in an attempt to enhance Jc. A 4.5 μm thick film irradiated with 1 MeV protons at a dose of 3×1014/cm2 has shown an increase of Jc by a factor of nearly 20–1.7×106A/cm2 corroborating the proposal that a lack of pinning centers in the grown thick films, due to their high crystalline quality, contributed to the observed decrease of Jc with increasing film thickness.