A novel method to improve the morphology of Bi2212 film by PVA-assisted Pechini sol-gel method

Bi2212 high-temperature superconducting thin films (HTSFs) have emerged as the most promising material for terahertz (THz) devices due to their intrinsic Josephson effect. Enhancing the surface smoothness of these films is crucial for their practical application. In this study, metal nitrates were utilized as the raw material to prepare Bi2212 HTSFs on SrTiO3 (100) substrates using the Pechini sol-gel method. The chelating agent ethylenediamine tetraacetic acid (EDTA) and the surfactant polyvinyl alcohol (PVA) were employed to improve the dissolution characteristics of Bi2212 solution. The influence of various parameters such as sintering temperatures, surfactant concentrations, and metal ion ratios was systematically investigated to assess the phase purity, crystallinity, surface morphology, and electrical properties of the Bi2212 superconducting thin films. The results demonstrated that a higher concentration of PVA led to reduced solubility of the Bi2212 solution. Notably, when the PVA concentration was set at 1 %, the fabricated Bi2212 thin film exhibited exceptional epitaxial properties, enhanced Bi2212 phase purity, reduced surface roughness, and higher Tc. These outcomes provide valuable insights for the development of Bi2212 HTSFs in superconducting devices, as they serve as a reference point for achieving optimal film characteristics.

Automated summary

Bi2212 high-temperature superconducting thin films (HTSFs) were prepared on SrTiO3 (100) substrates using metal nitrates as raw materials and the Pechini sol-gel method. EDTA and PVA were employed to improve the dissolution characteristics of Bi2212 solution. The effects of various parameters on film properties were systematically investigated, and it was found that a higher concentration of PVA led to reduced solubility of the Bi2212 solution. Notably, a 1% concentration of PVA resulted in exceptional epitaxial properties, enhanced Bi2212 phase purity, reduced surface roughness, and higher Tc for the fabricated Bi2212 thin film.