YBCO coated nickel-based tapes with various buffer layers

Abstract

Biaxially textured YBa 2 Cu 3 O 7 (YBCO) thin films, yttria stabilized zirconia (YSZ) and yttria (Y 2 O 3 ), CeO 2 buffer layers were grown in situ on NiO/Ni based substrates by Pulsed Injection MOCVD (PICVD) using monoglyme solutions of β-diketonates (Cu(thd) 2 , Ba(thd) 2 , Y(thd) 3 , Ce (thd) 2 , Zr(thd) 4 ). High quality textured nickel oxide layers have been prepared by SOE (Surface Oxydation Epitaxy) following an optimized recrystallisation-oxidation process.Thin YSZ/Y 2 O 3 biaxially textured buffer layers (thickness 200nm/200 nm) were deposited in a wide range of temperature (from 600°C to 800°C). Subsequent YBCO layers (thickness 750nm) on Ni/NiO/YSZ/Y 2 O 3 were grown epitaxially (ω-scan of YBCO FWMH=5°) and exhibited critical current densities Jc ≥3.10 5 A/cm 2 with a critical temperature Tc=90K and ΔTc ≤ 1 K. The best results were obtained for deposition temperatures of 600°C for YSZ, 675°C for Y 2 O 3 and 800°C for YBCO.