Defining optimal thickness for maximal self-field J(c) in YBCO/CeO2 multilayers grown on buffered metal

The effect of multilayering YBa2Cu3O6+x (YBCO) thin films with sequentially deposited CeO2 layers between YBCO layers grown on buffered metallic template is investigated to optimize the self-field critical current density J(c)(0) . We have obtained that the improvement in J(c)(0) clearly depends on the YBCO layer thickness and temperature, where at high temperature J(c)(0) can be increased even 50% when compared with the single layer YBCO films. Based on our experimental results and theoretical approach to the growth mechanism during multilayer deposition, we have defined a critical thickness for the YBCO layer, where the maximal self-field J(c)(0) is strongly related to the competing issues between the uniform and nonuniform strain relaxation and the formation of dislocations and other defects during the film growth. Our results can be directly utilized in the future coated conductor technology, when maximizing the overall in-field J(c)(B) by combining both the optimal crystalline quality and flux pinning properties typically in bilayer film structures.

Automated summary

The effect of multilayering YBCO thin films with sequentially deposited CeO2 layers on self-field critical current density J(c)(0) is investigated. The improvement in J(c)(0) depends on YBCO layer thickness and temperature, with a potential increase of 50% at high temperature compared to single layer films. A critical thickness for YBCO layer is determined based on experimental results and theoretical analysis of the growth mechanism, where the maximum self-field J(c)(0) is strongly influenced by the competing issues of strain relaxation and defect formation during film growth. These findings can be applied in future coated conductor technology to maximize overall in-field J(c)(B).