Biaxially textured YBa2Cu3O7−x films deposited on polycrystalline flexible yttria-stabilized zirconia ceramic substrates

Biaxially textured YBa2Cu3O7−x (YBCO) films were grown on polycrystalline flexible yttria-stabilized zirconia (YSZ) ceramic substrates (Ceraflex) buffered with MgO and LaMnO3 layers. These substrates were initially coated with silica glass to obtain a smooth surface and then biaxially textured MgO buffer layers were deposited by ion beam assisted deposition (IBAD-MgO). Lanthanum manganate (LMO) cap layers and YBCO layers were then deposited by the pulsed laser ablation method. Highly textured YBCO films with a full width half maximum (FWHM) of 6.75° in (1 1 0) phi scans and a FWHM ∼ 5° in (2 0 0) omega scans were obtained. An initial deposition yielded samples with a Tc > 88 K and a self-field magnetization Jc of 2 × 105 A/cm2 at 77 K. A secondary ion mass spectrometry (SIMS) depth profile of the samples indicated that with the present deposition condition, some La, Mn and Mg diffusion into the YBCO layers is possible and this may reduce the Jc in the self-field. The yield strength (YS) of uncoated Ceraflex substrates was compared with that of metallic substrates and it was found that Ceraflex substrates can have a YS at least 4-5 times higher than the YS of biaxially textured Ni-5 at.%W substrates and ∼1.5 times that of HastelloyTM substrates.