Pulsed laser deposition of YBCO coated conductor using Y₂O ₃ as the seed and cap layer

Although a variety of buffer layers have been routinely reported, a standard architecture commonly used for the YBa₂Cu₃O _7-x (YBCO) coated conductor is YBCO/CeO₂/YSZ/CeO ₂/substrate or YBCO/CeO₂/YSZ/Y₂O ₃/substrate where ceria is typically the cap layer. CeO₂ is generally used as only a seed (or cap layer) since cracking within the film occurs in thicker CeO₂ layers due to the stress of lattice mismatching, Y₂O₃ has been proposed as a seed and as a cap layer but usually not for both in a given architecture, especially with all layers deposited in situ. Yttrium oxide films grown on nickel by electron beam evaporation processes were found to be dense and crack free with good epitaxy. In this report, pulsed laser deposition (PLD) of Y₂O₃ is given where Y₂O₃ serves as both the seed and cap layer in the YBCO architecture. A comparison to PLD CeO₂ is provided. Deposited layers of the YBCO coated conductor are also grown by laser ablation. Initial deposition resulted in specimens on textured Ni substrates with current densities of more than 1 MA cm^-2 at 77 K, self-field.