Effect of Water, Acetone of Acids on Bi-System Superconductiong Film prepared by Use of Sol-Gel Method II

Abstract

We prepared Bi-Pb-Sr-Ca-Cu-O superconducting films on single crystal MgO substrate by sol-gel method. As the starting solution, we used the propionic or butyric acid solution prepared by solving acetates or 2223 phase powder. MgO substrate was coated with the starting solution using a spin coater and heated for 30min at 700°C. This process was repeated several times and the film was heated at 855°C for less than 24h. The film samples obtained from acetates-solute butyric acid were soaked in water or acetone in order to study their effect on Tc_o. The Tc_o of sample soaked for 24h in water was lower by 5K than that of sample before soaking(Tc_o=77K). For the films obtained from 2223 oxide-solute propionic acid, the percent of 2223 phase increased from 0 to 30% when the sintering duration at 855°C increased from 1 to 12h.