Enhanced Critical Current Density in Optimized High-Temperature Superconducting Bilayer Thin Films.

The superconducting and structural properties of bilayer thin films based on YBa 2 Cu 3 O 6+x /YBa 2 Cu 3 O 6+x +6%BaZrO 3 heterstructures have been studied. In a broad range of magnetic field strengths and temperatures, the optimal bilayer film comprises 30% YBCO at the substrate interface and 70% YBCO+6%BZO on the top. The critical current density measured for the optimal bilayer structure is shown to outperform the corresponding single layer films up to almost 60%. The obtained results are comprehensively discussed in the light of our previously published theoretical framework (E. Rivasto et al., J. Phys. Condens. Matter. 2023). We conclude that the bilayering provides an efficient and easily applicable way to further increase the performance and applicability of high-temperature superconductors in various applications. Consequently, the bilayer films should be seriously considered as candidates for the upcoming generation of coated conductors.