Study of Ta-doped CeO2 Buffer Layer for Coated Conductors

Abstract Ta-doped CeO 2 buffer layers were grown on the home-made textured Ni-5W substrates for YBCO coated conductors by a simple metal-organic deposition technique. The characterization of the samples was discussed. XPS results indicate that Ta 5+ is reduced into Ta 4+ prior to Ce 4+ , which is helpful to suppress the formation of holes and cracks in CeO 2 films from reducing Ce 4+ into Ce 3+ . Additionally, no new phase is found by doping Ta into CeO 2 , which indicates that Ta 4+ replaces the Ce 4+ position in CeO 2 lattice to form Ce 0.75 Ta 0.25 O 2 . The Ce 0.75 Ta 0.25 O 2 has a good out-of-plane and in-plane texture FWHM values for ω scan and ϕ scan are 4.38° and 6.67°, respectively. AES measurements show that no Ni element is detected on the surface of Ce 0.75 Ta 0.25 O 2 film, and a one-layer film has a thickness of about 70 nm. It is promising that the presently developed Ce 0.75 Ta 0.25 O 2 film can be used as a single multi-functional buffer layer for coated conductor.