YSZ buffer layers on large technical substrates

The ion-beam-assisted deposition (IBAD) of yttria-stabilized zirconia (YSZ) films was extended to large technical substrates such as ceramic plates, metallic tapes and metallic tubes to serve as templates for high-current carrying Y-Ba-Cu-O films. These YSZ films are deposited with dual-Kaufman-ion-source equipment. The coating of technical substrates large in comparison to the ion sources requires special measures to provide YSZ films of homogeneous texture quality. With respect to the special growth mechanism of YSZ, a homogenization of the in-plane texture can be achieved by simple movement of the substrate. Up to now we have been able to produce YSZ films on ceramic substrates (10 cm/spl times/10 cm) with a homogeneous in-plane texture of 17/spl deg/ FWHM and on a Ni-tape (1 cm/spl times/50 cm) with a FWHM of 21/spl deg/. The main aspects of the growth mechanism-the influence of the nucleation, the improvement of texture with increasing film thickness and homoepitaxial effects-and the surface morphology are investigated in detail with transmission electron microscopy (TEM) and atomic force microscopy (AFM).