Laser ablated buffer layers for YBCO-tape conductors

Biaxially oriented yttria stabilized zirconia (YSZ) and Pr6O11 buffer layers were grown at room temperature by Ion-Beam Assisted Laser Deposition (IBALD) on metal substrates. Dependent on deposition parameters, IBALD grown films showed in-plane orientations of about 10 degrees FWHM (full-width at half maximum) for both systems. In contrast to the YSZ system, where best in plane alignment is found for a [111] direction oriented parallel to the ion beam, the Pr6O11 system shows best in-plane alignment at nearly gracing incidence of the ion beam. An additional thin intermediate CeO2 layer improves the heteroepitaxial growth of YBCO on highly biaxially oriented YSZ films. Pulsed Laser Deposition (PLD) was also used to grow epitaxial CeO2 buffer layers directly on biaxially textured Ni-tapes. SIMS investigations showed an interdiffusion zone of about 0.5 mu m at standard deposition conditions, but no enhanced grain boundary diffusion could be observed.