Application of spray deposition techniques for fabrication of Sm-doped CeO2 thin films on biaxially textured Ni-W substrate

Abstract

Chemical and thermo-resistant buffer layers are commonly used to separate metal substrates and high-temperature superconductors (HTS). This ensures that no reaction occurs between the superconductor's precursor materials and the substrate metal during high-temperature HTS tape processing. Various materials and coating procedures are available, with each combination of buffer layers requiring specific characteristics. This paper reports a feasibility study into the development and use of simple, aerosol-based production methods of samarium-doped cerium thin films for subsequent use as a buffer layer between a Ni substrate and yttrium barium copper oxide (YBCO) superconductor. The suggested methods are very cost effective and hence attractive for commercial use. It was shown that different types of aerosol nebulisers can produce textured, pinhole-free films of high integrity and uniformity. Thickness of the films could be precisely controlled by the deposition time enabling achieving any required value starting from 40 nm. It was found that that the optimum film thickness is between 120 and 180 nm, and higher film thickness led to the surface cracking. Microstructural and crystallographic characteristics, and chemical composition of fabricated films are also reported and discussed.