Development of YBCO-coated conductors for electric power applications U. Balachandran * , M. Li, R.E. Koritala, B.F. Fisher, B. Ma Energy Technology Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 60439, USA Abstract Biaxially textured MgO template films have been fabricated on a Ni-based alloy substrate (Hastelloy C276) by in- clined-substrate deposition (ISD), using electron beam evaporation, at the high deposition rate of 120–300 nm/min. Bufferfilmsweresubsequentlydepositedonthesetemplatefilms,andYBCOfilmswerefinallydepositedbypulsedlaser deposition (PLD). Crystal textures of the YBCO films were examined by X-ray pole figure, /- and x-scans analysis. Goodin-planeandout-of-planetextureswereobserved,withMgO(002) /-scan full-width-at-half-maximum (FWHM) of 10.0° and x-scan FWHM of 5.5°, for a film deposited with an incline angle of 55°. YBCO films were epitaxially grown on ISD MgO-buffered Hastelloy C276 substrates by PLD. T c of 90 K with sharp transition and transport J c of 1:4  10 5 A/cm 2 were obtained on a 0.5-lm-thick YBCO film at 77 K in zero field. Ó 2002 Elsevier Science B.V. All rights reserved. Keywords: YBCO-coated conductor; Superconducting thin film; Inclined-substrate deposition; MgO; Biaxial texture 1. Introduction The development of YBCO-coated conductor technology is making possible the design and fab- ricationofsmaller,lighter,andmoreefficientpower devices such as motors, generators, transformers, transmission cables, and fault-current limiters that can be operated at temperatures approaching that ofliquidnitrogen[1–3].Biaxiallytexturedtemplate films, which are necessary for depositing YBCO films with high critical current density (J c ), have been fabricated by several techniques such as ion- beam-assisted deposition (IBAD), rolling-assisted biaxially textured substrates (RABiTS), and in- clined-substratedeposition(ISD).Comparedtothe former two processes, ISD produces textured films athighdepositionrates(120–300nm/min)andthat are independent of recrystallization properties of themetallicsubstrates.ISDisalsosimpler(without the need of an assistant ion source) and easier to accomplish [4–6]. In this paper, we report the growth mechanism, microstructure, dependence of the biaxial alignment of ISD MgO thin films on substrate incline angles, together with supercon- ducting properties of YBCO films deposited on these highly textured ISD MgO buffer layers fab- ricated on polished alloy substrates. 2. Experiments Biaxially textured MgO thin films were depos- ited on mechanically polished Hastelloy C276 Physica C 372–376 (2002) 869–872 www.elsevier.com/locate/physc * Corresponding author. Fax: +1-630-252-3604. E-mail address: balu@anl.gov (U. Balachandran). 0921-4534/02/$ - see front matter Ó 2002 Elsevier Science B.V. All rights reserved. PII:S0921-4534(02)00881-X