Fabrication of YBCO films on Ag substrate by TFA-MOD method
(College of Materials Science and Engineering,
Beijing University of Technology,
Key Laboratory of Advanced Functional Materials,
Ministry of Education, Beijing 100022, China)
Beijing University of Technology,
Key Laboratory of Advanced Functional Materials,
Ministry of Education, Beijing 100022, China)
Abstract: Biaxial aligned YBCO films have been successfully deposited on Ag {110}〈110〉 textured polycrystalline substrates by metal-organic decomposition (MOD) method using Trifluoroacetate Salt (TFA). The influence of firing temperature and Ag surface defects on phase purity and texture, surface morphology of YBCO films was studied. Holding temperature at 900 ℃ for 30 min benefits to improve orientation and connectivity of YBCO films. The surface of YBCO films deposited on unpolished Ag substrate has many holes and stripes, which are parallel to the rolling stripe on Ag substrates. To eliminate the rolling stripe on the Ag surface, Ag substrates were polished prior to films deposition. The film grown on polished Ag substrates has a smooth surface and good connectivity of grains without parallel stripes. The YBCO films have an onset of transition around 90K and critical current densities of 15 000 A/cm2.
Key words: YBCO; TFA-MOD; textured Ag； coated conductor