Statistically designed experimental study of sol–gel-based film coating scheme for high-temperature superconductor and buffer materials and related processing cost evaluation

At the University of Tennessee Space Institute (UTSI), processing factors that influence the epitaxial growth of LaAlO3 (LAO) on cubic-textured nickel substrates via sol–gel route were investigated using a Taguchi L12 experimental design. Through experimental data collected on omega FWHM, phi FWHM, and composition of orientations, a set of models was generated to characterize the epitaxial growth response to various processing factors. These factors included thermal processing time, temperature, atmosphere, nickel surface roughness, degree of precursor hydrolysis, withdrawal rate, and precursor solution concentration. Based on the results appropriate processing conditions were then identified to produce the greatest degree of epitaxial growth as defined by the non-dimensional term. In addition, preliminary processing cost was developed and compared with the other leading schemes based on methods such as evaporative electron beam, pulsed laser deposition, and metal organics chemical vapor deposition.