Effect of Hf addition on critical current density of (Y,Eu)Ba2Cu3.6O7-δ thin films prepared by trifluoroacetate metal organic deposition

The critical current density (Jc) performance of YBCO coated conductors (CCs) under magnetic field has become a considerable limitation for its commercial application in recent years. It is well known that the proper amount of element doping into the CCs is a convenient method to increase flux pinning and then to enhance the Jc. In the present work, we firstly introduce the co-doping of Eu and Hf and study the effect on the performance of YBa2Cu3.6O7-δ thin films. Three types of high temperature superconducting thin films, i.e., YBa2Cu3.6O7-δ, (Y,Eu)Ba2Cu3.6O7-δ and Hf doped (Y,Eu)Ba2Cu3.6O7-δ were prepared on the oxide buffered metallic substrates by using trifluoroacetate metal organic deposition (TFA-MOD). The component and structure of the as-prepared samples were characterized by X-ray diffraction (XRD), scanning electronic microscopy (SEM) and atomic force microscopy (AFM). Superconducting properties were measured with a SQUID magnetometer. It was revealed that the (Y,Eu)Ba2Cu3.6O7-δ thin films exhibit better out-plane and in-plane texture compared with the pure YBa2Cu3.6O7-δ thin film. The Jc of (Y,Eu)Ba2Cu3.6O7-δ thin film was improved compared with pure YBCO thin film. In case of Hf doping, however, the biaxial texture became worse while the in-field Jc performance was enhanced, implying the increase of flux pinning with proper Hf addition.