CeO/sub 2/ buffer layers deposited by pulsed laser deposition for TFA-MOD YBa/sub 2/Cu/sub 3/O/sub 7-X/ superconducting tape

Abstract

A CeO/sub 2/ buffer layer was deposited by the pulsed laser deposition (PLD) method on a YSZ single crystal substrate and an IBAD-Gd/sub 2/Zr/sub 2/O/sub 7/ substrate. It was investigated in terms of the effect of the CeO/sub 2/ layer thickness for YBa/sub 2/Cu/sub 3/O/sub 7-X/ (YBCO) coated conductors by the metalorganic deposition method using trifluoroacetates (TFA-MOD). The grain alignment, delta phi, and surface roughness, R/sub a/, of CeO/sub 2/ layers were improved with increasing the thickness for both kinds of substrates of a YSZ single crystal and an IBAD-Gd/sub 2/Zr/sub 2/O/sub 7/ substrate. Especially the improvement of the qualities of the CeO/sub 2/ layer on the IBAD substrate was remarkable. The initial value of delta phi was 12 degree at the surface of the IBAD-Gd/sub 2/Zr/sub 2/O/sub 7/ layer without a CeO/sub 2/ layer while it decreased to 4 degree after 600 nm thick CeO/sub 2/ layer deposition by PLD. Consequently, the J/sub c/ value of the YBCO on the CeO2 buffered IBAD-Gd/sub 2/Zr/sub 2/O/sub 7/ metallic substrate exhibited the value as high as 2.9 MA/cm/sup 2/ 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.