The intrinsic Josephson effect of Bi-2212 superconducting thin films prepared by sol-gel method

In this paper, Bi2Sr2Ca1Cu2O8+sigma, (Bi-2212) superconducting thin films was prepared by using a sol-gel method on a LaAlO3 (LAO) single crystal substrate, with acetates of bismuth, strontium, calcium, and copper as the starting raw materials. A step structure was specifically designed to measure the intrinsic Josephson effect. The microstructure of the Bi-2212 thin films and their epitaxial growth on the LAO substrate were analyzed by a Cs-corrected transmission electron microscope (Cs-TEM) with an atomic-level resolution and the electrical properties were measured. The results showed that the prepared Bi-2212 thin films had good epitaxial growth characteristics and good in-plane and out-plane growth texture and that its critical transition temperature, T-c, was 87 K. The interface between the substrate and the film was well-defined; the films grow epitaxially on the substrate from the CuO layer, with a highly ordered atom arrangement. The I-V characteristic curve of the prepared step micro-bridging sample showed zero-voltage overcurrent phenomenon, and the critical current was 2.3 mA. In addition, multiple current-voltage jumps were observed on the curve, indicating that the prepared biaxial texture thin films showed the intrinsic Josephson effect.

Automated summary

In this study, Bi2Sr2Ca1Cu2O8+sigma (Bi-2212) superconducting thin films were successfully prepared on LaAlO3 single crystal substrate using a sol-gel method. The thin films exhibited good epitaxial growth characteristics, with a critical transition temperature of 87 K, and showed the intrinsic Josephson effect.