Fabrication of Y_2O_3 buffer layer on polished Ni substrates for YBCO superconducting tape

1IntroductionIn recent years,worldwide research efforts have been made to develop YBCOsuperconducting tapes.Two promising approaches for the profitable production of long YBCOtapes that are suitable for carryinghigh currents in magnetic fields are RABi TS(Rolling Assisted Biaxially Textured Substrates)1]and IBAD(Ion Beam Assisted Deposition)methods2].In RABi TS process,the necessarily strong biaxial texture ofthe YBCOfil mis achieved by epitaxial growth of buffer layers andthe …

Fabrication of Y_2O_3 buffer layer on polished Ni substrates for YBCO superconducting tape

Highly cube textured Ni tapes are produced by heavy cold rolling and recrystallization annealing. The textured nickel tapes have been proven to be suitable substrates for YBCO superconducting tape. Nevertheless, rolling damage and grain boundary grooves on Ni influence the epitaxial growth of highly textured buffer and YBCO layers. The polishing of the Ni substrate surface may play a crucial role in making it beneficial to epitaxial film deposition. In our work, several polishing methods were adopted on Ni to reduce the depth of rolling damage and grain boundary grooves. On the polished Ni substrates, textured Y_2O_3 buffer layers were deposited using RF sputtering. XRD results show that in-plane texture of Y_2O_3 films will minish with the decreasing of the Ni substrate surface roughness. AFM results show that average grain size of the Y_2O_3 film is biggest and surface is coarse in film on flatter Ni surface.