LAUSR

To develop a low-cost coated conductor, a new wire architecture using conductive buffer layers and a metal tape with high conductivity has been proposed. Nb-doped SrTiO3 (Nb–STO) was chosen as the conductive buffer layer. A high JC of 2.5 MA/cm2 at 77 K under a self-magnetic field was demonstrated using a Nb-STO buffer layer and a cube-textured Cu and stainless-steel laminate tape as a metal tape with high conductivity. Considering the industrial production of wires, it is preferable to have many suitable materials. Thus, Nb-doped TiO2 (Nb–TiO2) was examined as a new conductive buffer layer. However, it was found to be difficult to grow a well biaxially aligned YBCO layer on a single Nb-TiO2 buffer. Therefore, in this paper, buffer layers combining both Nb–STO and Nb–TiO2 were prepared and an YBCO layer was deposited on this buffer layer by PLD with the purpose of realizing a superior conductivity characteristic to that of the single Nb–STO buffer layer. It was found that the combined buffer layer has potential use as a conductive buffer layer. However, the process must be optimized to increase the benefit of adding Nb–TiO2 to Nb–STO.