Preparation and Flux-Pinning Properties of Multilayered Yttrium Barium Copper Oxide Thin Films Containing Alternating Barium Zirconate and Yttria Nanostructures

Multilayered yttrium barium copper oxide (YBCO) thin films grown by the pulsed laser deposition technique provide the possibility for independently tailoring the nanoscale artificial pinning centers embedded in individual layers. This enables engineering of artificial pinning centers in YBCO thin films for optimizing their flux-pinning properties. In this work, we combined barium zirconate (BaZrO₃) and yttria (Y₂O₃) nanostructures into multilayered YBCO thin films by alternating ablation of YBCO + BaZrO₃ and YBCO + Y₂O₃ composite targets. The layers containing BaZrO₃ nanostructures have a different thickness from those containing Y₂O₃ nanostructures. A highly epitaxial multilayered YBCO thin film, comprising five alternating layers of YBCO + BaZrO₃ and YBCO + Y₂O₃, has been prepared on a lanthanum aluminate (LaAlO₃) (100) substrate. This multilayered YBCO thin film exhibited strong flux-pinning properties. This work provides a preliminary step towards engineering of artificial pinning centers in YBCO thin films.