Enhanced flux pinning in $YBa2Cu3O7−δ$ films by nanoscaled substrate surface roughness Available to Purchase

Nanoscaled substrate surface roughness is shown to strongly influence the critical current density $(Jc)$ in $YBa2Cu3O7−δ$ (YBCO) films made by pulsed-laser deposition on the crystalline $LaAlO3$ substrates consisting of two separate twin-free and twin-rich regions. The nanoscaled corrugated substrate surface was created in the twin-rich region during the deposition process. Using magneto-optical imaging techniques coupled with optical and atomic force microscopy, we observed an enhanced flux pinning in the YBCO films in the twin-rich region, resulting in a $∼30%$ increase in $Jc$⁠, which was unambiguously confirmed by the direct transport measurement.