Nanoscale analysis of the interface structure and strain of the Bi2Sr2CaCu2O8+?/LaAlO3 heterogeneous system

The interface structure and strain significantly affect the performance of superconducting films with het-erogeneous structures. In this context, the interface structure and strain of the Bi2Sr2CaCu2O8+delta super-conducting thin film fabricated using the sol-gel technique were investigated through aberration-corrected HAADF-STEM, EDX, and GPA. The results revealed that the interfacial atomic sequence was LaAlO3 (AlO2 terminated)-SrO-(Bi2212)n, where the -SrO-layer was the nucleation layer, and (Bi2212)n included the intergrowth phases of Bi2201, Bi2212, and Bi2223. The combined effect of the different lattice mismatch relaxation methods, such as lattice distortion and stacking fault, caused the final Bi2212 film to undergo an average in-plane compressive strain (epsilon xx similar to -0.4501 %) compared to bulk Bi2212. In addition, the in-plane compressive strain related to the structure of the Bi2212/LaAlO3 heterostructure was gradually released as the distance from the heterointerface increased.(c) 2023 Elsevier B.V. All rights reserved.

Automated summary

It was found that the performance of superconducting films with heterogeneous structures is significantly affected by the interface structure and strain. The interface structure and strain of a Bi2Sr2CaCu2O8+delta superconducting thin film fabricated using the sol-gel technique were investigated. The results showed that the interfacial atomic sequence and lattice mismatch relaxation methods play a role in the compressive strain of the film.