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ADP analyzed the samples by AFM and optical microscopy and suggested the study. XS produced the samples. GG developed the theoretical calculations. LF and GG coordinated the investigation. ADP and GG jointly wrote the manuscript. All authors read and approved the final version of the manuscript.”
“Background Second-generation high-temperature superconducting (HTS) coated conductors based on ReBa2Cu3O7 − δ (REBCO, RE = Y, Gd, Sm, etc., rare earths) films are coming into practical applications for motors, fault current limiters, generators, and transformers [1, 2]. High critical current

(I c) is needed for many HTS applications. Apparently, enhancing the thickness of (RE) BCO films is the simplest method. However, there is an obstacle for this way as there is a current density (J c) decreasing phenomenon as films become thicker [3]. Such a falloff of J c is found in ReBa2Cu3O7 − δ films fabricated by different methods, such as pulsed laser deposition [4], hybrid liquid-phase epitaxy [5], Ba-F-based methods [6], and chemical solution deposition by ink-jet printing [7]. Several possible reasons for the so-called ‘thickness effect’ of J c have been advanced. These include a-axis Amisulpride growth, the increase in surface roughness, and porosity. Another reasonable interpretation of the thickness effect of J c has been Cytoskeletal Signaling inhibitor proposed by Foltyn et al. [8]. They attributed this to misfit dislocations near the interface between the superconductor and the substrate. The same research group reported that by inserting several thin CeO2 layers, the thickness effect can be overcome in some extent [9]. The suppressed thickness effect may be due to much more interfaces between the superconductor and the substrate in the multilayer compared with the single layer.