INSTITUTE OF PHYSICS PUBLISHING SUPERCONDUCTOR SCIENCE AND TECHNOLOGY Supercond. Sci. Technol. 16 (2003) 1305–1309 PII: S0953-2048(03)67719-5 MOD approach for the growth of epitaxial CeO 2 buffer layers on biaxially textured Ni–W substrates for YBCO coated conductors M S Bhuiyan 1,2 , M Paranthaman 2 , S Sathyamurthy 1 , T Aytug 1 , S Kang 1 , D F Lee 1 , A Goyal 1 , E A Payzant 1 and K Salama 2 1 Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA 2 University of Houston, Houston, TX 77204, USA Received 11 August 2003, in final form 15 September 2003 Published 17 October 2003 Online at stacks.iop.org/SUST/16/1305 Abstract We have grown epitaxial CeO 2 buffer layers on biaxially textured Ni–W substrates for YBCO coated conductors using a newly developed metal organic decomposition (MOD) approach. Precursor solution of 0.25 M concentration was spin coated on short samples of Ni–3 at%W (Ni–W) substrates and heat-treated at 1100 ◦ C in a gas mixture of Ar–4%H 2 for 15 min. Detailed x-ray studies indicate that CeO 2 films have good out-of-plane and in-plane textures with full-width-half-maximum values of 5.8 ◦ and 7.5 ◦ , respectively. High temperature in situ XRD studies show that the nucleation of CeO 2 films starts at 600 ◦ C and the growth completes within 5 min when heated at 1100 ◦ C. SEM and AFM investigations of CeO 2 films reveal a fairly dense microstructure without cracks and porosity. Highly textured YSZ barrier layers and CeO 2 cap layers were deposited on MOD CeO 2 -buffered Ni–W substrates using rf-magnetron sputtering. Pulsed laser deposition (PLD) was used to grow YBCO films on these substrates. A critical current, J c , of about 1.5 MA cm −2 at 77 K and self-field was obtained on YBCO (PLD)/CeO 2 (sputtered)/YSZ (sputtered)/CeO 2 (spin-coated)/Ni–W. 1. Introduction Chemical solution processing techniques have emerged as viable low-cost nonvacuum methods for producing ceramic oxide powders and films [1–3]. The most commonly used solution techniques are (i) sol–gel processes that use 2-methoxyethanol as a reactant and solvent; (ii) hybrid processes that use chelating agents such as acetylacetonate or diethanolamine to reduce alkoxide reactivity and (iii) metal organic decomposition (MOD) techniques that use high-molecular-weight precursors and water insensitive carboxylates, 2-ethylhexanoyates, etc [4]. These processes offer many desirable aspects, such as precise control of metal oxide precursor stoichiometry and composition, ease of formation of epitaxial oxides, relatively easy scale-up of the film and low cost. In recent years various rare-earth oxides (RE 2 O 3 ) and rare-earth zirconium oxide (RE 2 Zr 2 O 7 ) films have been grown epitaxially on biaxially textured Ni and Ni–W substrates by solution based methods [5–7]. In the rolling-assisted biaxially textured sub- strates (RABiTS) approach, four-layer architecture of CeO 2 /YSZ/Y 2 O 3 /Ni/Ni–W is used to fabricate long lengths of buffered tapes. The purpose of the buffer layers is to retard oxidation of Ni, to reduce the lattice mismatch between Ni and YBCO and also to prevent diffusion of Ni into YBCO. We have chosen cerium oxide, CeO 2 as a potential buffer layer for this study. CeO 2 has a fluorite CaF 2 structure with a lattice parameter of 5.41 ˚ A and it gives better chemical compatibility with Ni–W substrates and also good lattice matching with YBCO. Thin films of CeO 2 have been grown by various vacuum [8–11] and nonvacuum [12] based deposition techniques on rolled-Ni substrates. In this paper, we describe our successful development of the growth of CeO 2 seed layer on rolled Ni–W substrates by MOD 0953-2048/03/111305+05$30.00 © 2003 IOP Publishing Ltd Printed in the UK 1305