Synthesis and characterization of buffer layers and yttrium barium copper oxide superconducting coatings by chemical solution deposition method

The objective of this study is to fabricate YBCO/buffer layers/Ni superconducting tapes by chemical solution deposition (CSD) techniques using metal alkoxide precursors for high magnetic field applications. With this aim, cerium oxide, gadolinium oxide and europium oxide buffer layers were firstly coated on textured nickel tape by sol-gel method, and then YBCO films were prepared on buffered nickel tapes through the TFA-MOD and flourine-free MOD methods. In order to evaluate solution characteristics which affect thin film structure; turbidity, pH values, wettability and rheological properties of the prepared solutions were measured by turbidimeter, pH meter, contact angle goniometer and rheometer machines before coating process. In order to use suitable process regime and to define chemical structure and reaction type of intermediate temperature products, Differential Thermal Analysis-Thermogravimetry (DTA-TG) and Fourier Transform Infrarared (FTIR) devices were used in the film production. Phase identification of the films was performed by using X-Ray Diffraction (XRD) and surface morphology was investigated using Scanning Electron Microscopy with an Energy Dispersive X- ray spectroscopy (IXRF System EDS) system attachment. Adhesion properties of buffer layers and superconducting films were determined by a scratch tester. Thickness measurement of the buffer films were investigated using refractometer and spectrophotometer devices. It was concluded that highly textured cerium oxide, gadolinium oxide and europium oxide buffer layers were fabricated on textured Ni tape by sol-gel technique and YBCO superconducting films successfully were deposited on buffered nickel tape using flourine-free sol-jel method.