Laser deposition of YBCO on long-length technical substrates

YBCO films with a high-quality in-plane texture have been grown on different Ni, yttria-stabilized zirconia (YSZ) and stainless steel (SS) substrates using a modified pulsed-laser deposition technique. A biaxially textured buffer of YSZ grown by ion-beam-assisted deposition was employed as a template for the YBCO film as well as a diffusion barrier. X-ray and TEM analyses were employed to understand the growth mechanisms. For short Ni substrates (10/spl times/10 mm), critical current densities J/sub c/ up to 2 MA/cm/sup 2/ (at 77 K, 0 T) were observed. Long YBCO coated samples with lengths up to 0.5 m were manufactured on Ni tapes (10 mm wide) and tubes (r=4-7 mm). Contactless measurements of the critical parameters were provided by a third-harmonic method. By bending experiments of YBCO films with external strain loading, J/sub c/ was found to be reversible in the range of strains between -0.5% and +0.5% under tension and compression, with a pronounced maximum under compressive strains.