Preparation and characterization of solution deposition planarized Y2O3-Al2O3 compound seed layer for coated conductors

In this work, we have successfully fabricated the second-generation YBa2Cu3O7 (YBCO)-coated conductors on the solution deposition planarization (SDP) yttrium oxide and aluminum oxide (Y2O3-Al2O3, YAlO) templates. Distinguishing from commercially available coated conductors, the SDP-YAlO process employs chemical solution deposition to fabricate multi-layer amorphous oxides on polycrystalline metal substrates, presenting a cost-effective alternative to replace sputtering-Al2O3, sputtering-Y2O3, and electrochemical polishing processes. The detailed SDP-YAlO fabrication process has been studied systematically. The YAlO seed layer exhibits smooth and flat surface morphology with an optimal root mean square roughness (RMS) of 1.6 nm over a 5 mu m x 5 mu m area, indicative of a smooth surface. Furthermore, the YBCO functional layer was deposited on ion beam-assisted deposition (IBAD) MgO buffer layers, utilizing both SDP-Y2O3 and SDP-YAlO as seed layers. The critical current (J(c)) uniformity of YBCO films on SDP-YAlO is much better that those on SDP-Y2O3, indicating the potential of SDP-YAlO as a promising seed layer for YBCO-coated conductors.