The Influence of Surface Morphology of Buffer Layer on the Critical Current Density in YBCO Coated Conductors

Jie Xiong,Yudong Xia,Yan Xue,Kai Hu,Xiaohui Zhao,Bowan Tao,Fei Zhang

doi:10.1155/2013/673948

Abstract

1 μm-thickYBa2Cu3O7-δ(YBCO) films were grown on the Y2O3/yttria stabilized zirconia (YSZ)/CeO2buffer layers with different surface morphologies using direct-current sputtering. The critical current density (Jc) value of YBCO was 1.1 MA/cm2when the root mean square surface roughness (Rrms) of the buffer layer was 2.5 nm. As theRrmsof the buffer layer increased to 15 nm, theJcdecreased to 0.3 MA/cm2. X-ray diffraction and scanning electron microscopy showed the strong relevance of the evolution of the structure and surface morphologies of YBCO films with the buffer layer of differentRrms. A model was proposed to explain the influence of surface morphology on the superconducting properties of YBCO films.

Highlights

There are more efforts focusing on the fabrication of high performance YBa2 Cu3 O7-δ (YBCO) coated conductors on flexible metallic substrates [1, 2]
We investigated in detail the impact of the surface morphologies of buffer layers on the superconducting properties in YBCO
Textured {100} ⟨100⟩ Ni-5at.%W alloy (NiW) tapes were used in this study, which were supplied from EVICO

Summary

Introduction

There are more efforts focusing on the fabrication of high performance YBa2 Cu3 O7-δ (YBCO) coated conductors on flexible metallic substrates [1, 2]. The application of 2nd generation coated conductors requires higher current carrying capacity To reach this goal, a high critical current density (Jc ) must be maintained in thick (>1 μm). Typical tri-layer stack of CeO2 /yttrium stabilized zirconia (YSZ)/Y2 O3 is one of the mostly explored architectures [7] Y2 O3 acts to transfer the biaxial texture from the RABiTS substrate to the YBCO layer; the YSZ layer is used as a barrier to prevent the interdiffusion between oxides and metal substrate; the CeO2 cap layer on YSZ layer provides good lattice matching and an epitaxial growth template for depositing the YBCO layer. We investigated in detail the impact of the surface morphologies of buffer layers on the superconducting properties in YBCO films

Experimental Details

Results and Discussion

Conclusions