Mixed Artificial Pining Centers by Single-Doping BaZrO $_{\text{3}}$ and Double-Doping BaZrO $_{\text{3}}$+Y$_{\text{2}}$ O$_{\text{3}}$ YBa $_{\text{2}}$Cu $_{\text{3}}$O $_{\text{7}}$−x on Flat and Vicinal Substrates

Generation of nanoscale artificial pinning centers (APCs) with mixed morphologies of one-dimensional (1-D) (nanorods in c-axis), 2-D (nanoplates in ab-plane), and 3-D (nanoparticles) in YBa 2 Cu 3 O 7-X (YBCO) films and coated conductors is important towards achieving strong pinning with minimal angular dependence on the magnetic field. In this paper, we explore the combination of the two effective methods for this purpose: double-doping of two different APC materials to achieve 1-D APC+3-D APC and straining YBCO lattice using vicinal substrates to achieve 1-D APC+2-D APC. Specifically, we have carried out a comparative study on 6 vol. % BaZrO 3 (BZO) single-doped and 6 vol. % BZO+3 vol. %Y 2 O 3 double-doped YBCO nanocomposite films on (100) SrTiO 3 (STO) single crystal flat and 5° vicinal STO substrates. The angular dependence of the critical current density J c was found to correlate well with the APC landscape tuned by the double-doping and vicinal growth.