Defining optimal thickness for maximal self-field J c in YBCO/CeO 2 multilayers grown on buffered metal.

The effect of multilayering YBa 2 Cu 3 O 6+x (YBCO) thin films with sequentially deposited CeO 2 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.&#xD.