Sol-gel Tb2O3 buffer layers on Ni tapes for YBCO coated conductors

In this study, processing of Tb2O3 buffer layers on textured Ni tapes were evaluated for YBa2Cu3O7-x (YBCO) coated conductor. A.solution deposition, process was used to grow textured Tb2O3 buffer layers on the Ni tapes. The solution was prepared using Tb-2, 4-pentanedionate precursor, methanol as solvent, chelating agents and a solution modifying chemical, triethanolamine (TEA). Biaxially textured Ni substrates were dipped into the solution by a reel-to-reel sol-gel dip coating system. The amorphous thin films were dried at 300degreesC for 30 sec and then heat-treated at 500degreesC for 2 min in air using an in-line three-zone furnace: The films were annealed at temperature range of 900degreesC and 11.70degreesC for 10 to 20 min under 4%H-2-Ar gas flow. The textured buffer layers were obtained using TEA onto the textured Ni tapes at 1150degreesC for 10 minutes. The Tb2O3 (222) pole figure revealed a single-cube-on-cube texture. The omega and phi scans indicated good out-of-plane and in-plane orientations. DTA results pointed out that Tb based gel film transformed to oxide structure at temperature range of 350degreesC and 410degreesC. Microstructures of the Tb2O3 films were investigated by Environmental Scanning Electron Microscope (ESEM), and the films were dense, smooth and. free from cracks and pinholes.