Strongly enhanced flux pinning in the YBa₂Cu₃O_{7 -x} films with the co-doping of BaTiO₃ nanorod and Y₂O₃ nanoparticles at 65 K

YBa₂Cu₃O_{7 - x} (YBCO) films with co-doping BaTiO₃ (BTO) and Y₂O₃ nanostructures were prepared by metal organic deposition using trifluoroacetates (TFA-MOD). The properties of the BTO/Y₂O₃ co-doped YBCO films with different excess yttrium have been systematically studied by x-ray diffraction (XRD), Raman spectra, and scanning electron microscope (SEM). The optimized content of yttrium excess in the BTO/Y₂O₃ co-doped YBCO films is 10 mol.%, and the critical current density is as high as ∼17 mA/cm² (self-field, 65 K) by the magnetic signal. In addition, the Y₂Cu₂O₅ was formed when the content of yttrium excess increases to 24 mol.%, which may result in the deterioration of the superconducting properties and the microstructure. The unique combination of the different types of nanostructures of BTO and Y₂O₃ in the doped YBCO films, compared with the pure YBCO films and BTO doped YBCO films, enhances the critical current density (J_C) not only at the self-magnetic field, but also in the applied magnetic field.