Texturing influence of process parameters in sol–gel Tb 2O 3 buffer layers on Ni tapes for YBCO coated conductors

Abstract

In this study, texturing influence of process parameters in sol–gel Tb 2O 3 buffer layers on textured Ni tapes was evaluated. A solution deposition process was used to grow epitaxial Tb 2O 3 buffer layers on the Ni tapes for YBa 2Cu 3O 7−x (YBCO) coated conductors. The Tb 2O 3 precursor solution was prepared using solvent, chelating agents and modifying chemical liquid materials. The solution was dip-coated onto the textured Ni substrates by a reel-to-reel sol–gel process. The amorphous thin films were dried at 300 °C for 30 s and then heat-treated at 500 °C for 2 min in air in the reel-to-reel sol–gel set up with a 3-zones furnace. The calcined films were annealed at temperature range of 750 and 1170 °C for 10–30 min under three different atmospheres. X-ray diffraction of the buffer layers indicated a strong c-axis orientation on the Ni tape substrate. The textured buffer layers were produced onto the textured Ni tapes at 1150 °C for 10 min under 4% H 2–Ar gas flow thereby using modifying triethanol amin. Environment scanning electron microscopy images of the Tb 2O 3 buffer layer showed crack-free, pinhole-free, dense and smooth microstructure.