High $I_{\rm c}$ in YBCO Films Grown at Very High Rates by Liquid Mediated Growth

Abstract

YBa2Cu3O7-x (YBCO) thick films were grown by hybrid liquid phase epitaxy (HLPE) on (001) SrTiO3 (STO) substrates. With introduction of Au into the film via diffusion from a 5 mol.% 100 nm thick Au-doped STO buffer, self-field Jcs at 77 K of ~ 2.4 MAcm-2 and I cs up to 700 A/cm-width of were achieved. The J c value is virtually independent on thickness and growth rates are extremely high ( ~ 1 mum/min) without the need for post-growth processing. From transmission electron microscopy (TEM), Y2O3 nano-cloud extended defects ( ~ 100 nm size), but < 100 nm apart, were identified as the pinning defects in the films. The single crystal results were successfully translated to tapes, giving self-field Ics of around 300 A/cm-width.