Dominant factors for the pinning enhancement by large artificial partial and complete antidots in superconducting films

Abstract

Partially (blind) or fully perforated antidots (BADs or ADs, respectively) fabricated by laser lithography and ion beam etching in superconducting YBa2Cu3O7 (YBCO) films possess a cumulative circumference wall surface, which is found to be responsible for pinning vortices and/or magnetic flux, whereby increasing the critical current density (Jc) relative to corresponding plain (unpatterned) films. Using a variety of contrastingly shaped, relatively large 2–5 μm BADs and ADs, the Jc of YBCO thin films has been effectively increased within the relatively narrow band of wall surfaces of antidots, independent whether patterns are AD or BAD type. Independence of antidot types indicates that enhancement is insensitive whether magnetic flux is inside the ADs, or vortices are inside the BADs. Within this AD wall surface band region a clear shape dependence also emerges. This finding may also provide a guide for superconducting devices requiring maximal Jc and reduced associated vortex movement noise.