High Quality YBCO Film Growth on SrTiO_3-Buffered LaAlO_3 Substrate by Full Solution Method

摘要

A full solution method has been developed as a low cost process of YBa_2Cu_3O_(7-x)(YBCO) coated conductor fabrication.In this study,highly biaxially textured SrTiO_3 (STO) buffer layers were fabricated on LaAlO_3 (LAO) single crystal substrates by sol-gel method using metal alkoxides as the staring precursor materials.High quality YBCO superconducting film was then fabricated on STO-buffered LAO substrate by trifluoroacetic metalorganic deposition (TFA-MOD) method.For the YBCO superconducting film,only (001) diffraction peaks can be detected by XRD (X-ray diffraction) analysis with no other phases detectable.Especially,In- plane texture of YBCO film is improved compared to that of STO buffer layer from phi scans analysis,which indicates the self-epitaxy phenomenon explained by considering interracial energy.STO and YBCO films both show c-axis oriented grains growt.h and have uniform surface microstructure.A critical transition temperature, T_c(R=0) of 89.5 K and a critical current density of 2 mA/cm^2 (77 K,self-field) were obtained for a 0.2μm thick YBCO film on STO-buffered LAO substrate.No reaction between YBCO and STO was detected by XRD analysis.This full solution process may provide a promising low cost fabrication route for YBCO coated conductors on metal tape.