Preparation of Conductive Buffer Architectures Based on IBAD-TiN

Ion beam assisted deposition (IBAD) was used in combination with pulsed laser deposition to develop a conductive biaxially textured buffer architecture based on IBAD-TiN for coated conductor applications. Highly textured TiN layers were prepared on Hastelloy substrates with an amorphous Y₂O₃ seed layer. The cube textured nucleation layer was preserved to higher thicknesses using homoepitaxial growth. A double layer of Au and Ir was used to reduce the lattice misfit between TiN and YBCO. Finally, a 120 nm thick Nb:SrTiO₃ layer was deposited to ensure the epitaxial growth of the superconducting YBCO layer at higher oxygen pressures. In-situ RHEED measurements revealed an undisturbed epitaxial growth of the complete buffer layer stack. The buffered tape was successfully used for the deposition of a 300 nm thick YBa₂Cu₃O_7-x layer, showing an in-plane FWHM value of 7.2^deg and a critical temperature T _c of about 88 K. The results are promising for the development of a completely electrical conductive buffer architecture based on the IBAD approach.