YBa2Cu3Ox-SrTiO3 multilayer approach on textured Ni-W tapes: Morphology, structure and critical current density improvement

• Multilayer structures based on YBCO were deposited using PLD on Ni-W substrates.
• Multilayer epitaxial structure allows maintaining high Jc in thin film.
• Interlayers serve as stop layers to morphology and microstructure degradation.
• This method allows multiplying critical current with number of YBCO layers.
• Application of this approach creates opportunities for coated conductor development.

Multilayer epitaxial structure YBa2Cu3Ox–interlayer–YBa2Cu3Ox is a promising architecture for YBa2Cu3Ox (YBCO) superconductors. We formed single YBCO layers and multilayer epitaxial structures YBCO–interlayer–YBCO by pulsed laser deposition method on the cube textured Ni-W tapes. The use of SrTiO3 interlayers enabled to stop YBCO film morphology and microstructure degradation and maintain high critical current density (Jc). Jc in 1 μm thick multilayer film composed of four 250 nm thick YBCO layers is comparable to Jc in single-layer 250 nm thick YBCO film. Application of this method allows overcoming such fundamental problem as degradation of Jc in thick films and multiplying critical current with number of YBCO layers.