CeO2 buffer layers deposited by pulsed laser deposition for TFA-MOD YBa2Cu3O7-x superconducting tape

A CeO₂ buffer layer was deposited by the pulsed laser deposition (PLD) method on a YSZ single crystal substrate and an IBAD-Gd₂Zr₂O₇ substrate. It was investigated in terms of the effect of the CeO₂ layer thickness for YBa₂Cu₃O_7-X (YBCO) coated conductors by the metalorganic deposition method using trifluoroacetates (TFA-MOD). The grain alignment, delta phi, and surface roughness, R_a, of CeO₂ layers were improved with increasing the thickness for both kinds of substrates of a YSZ single crystal and an IBAD-Gd₂Zr₂O₇ substrate. Especially the improvement of the qualities of the CeO₂ layer on the IBAD substrate was remarkable. The initial value of delta phi was 12 degree at the surface of the IBAD-Gd₂Zr₂O₇ layer without a CeO₂ layer while it decreased to 4 degree after 600 nm thick CeO₂ layer deposition by PLD. Consequently, the J_c value of the YBCO on the CeO2 buffered IBAD-Gd₂Zr₂O₇ metallic substrate exhibited the value as high as 2.9 MA/cm² at 77 K and 0 T. This result implies that a high rate deposition by PLD could be used for further texture evolution even after thin film IBAD deposition which could result in shortening of the overall production time for the buffer layers deposition.