Optimization of Surface Morphology of Bi2212 Films Prepared by Pva Assisted Pechini Sol-Gel Method

Abstract

Bi2212 high superconducting thin films (HTSF) have been considered the most promising candidate material for the terahertz (THz) device due to its intrinsic Josephson effect. It is essential to improve the surface smoothness of the film for the application of devices. In this work, metal nitrates were used as the raw material to prepare Bi2212 HTSFs on SrTiO3 (100) substrates using the Pechini sol-gel method. The ethylenediamine tetraacetic acid (EDTA) and polyvinyl alcohol (PVA) were applied as chelating agents and surfactants, respectively. The dissolution characteristics of different PVA concentrations in Bi2212 solution were systematically studied. In this process, varied sintering temperatures, surfactant concentrations, and metal ion ratios were used to specifically explore the phase purity, crystallinity, surface morphology, and electrical characteristics of Bi2212 superconducting thin films. The findings demonstrated that less Bi2212 solution could dissolve the more PVA was present. When the concentration of PVA was 1%, the fabricated Bi2212 thin film displayed excellent epitaxial properties, higher Bi2212 phase purity, lower surface roughness and higher Tc, which will enable the deployment of Bi2212 HTSFs in superconducting devices by serving as a reference.

Keywords: Pechini sol-gel method, Bi2212 HTSF, PVA, Surface roughness, Electrical properties