Preparation of high purity 110 K phase in the Bi(Pb)-Sr-Ca-Cu-O superconductor using the modified citrate process

✍ Scribed by Yang Kook Sun; Wha Young Lee

• Publisher: Elsevier Science
• Year: 1993
• Tongue: English
• Weight: 478 KB
• Volume: 212
• Category: Article
• ISSN: 0921-4534
• DOI: 10.1016/0921-4534(93)90483-7

✦ Synopsis

The superconducting Bi (Pb)-Sr-Ca-Cu-O system, with the high-T¢ phase, was prepared by the modified citrate process using an aqueous solution of metal nitrate containing citric acid and tartaric acid. It was found that transparent sols were obtained from the solution of initial pH of 7.6-9 and a molar ratio of C4H~Or/Cu of 0.45 to 1. The mechanisms of forming the low-T¢ phase as well as the high-T¢ phase were confirmed by FT-IR spectroscopy, X-ray diffraction and scanning electron microscopy. The modified citrate process produced much more high-T¢ phase than the citrate process when the sintering conditions were identical and its transition temperature, 108 K, was much higher.