Effect of Oxygen Partial Pressure on Superconducting Properties of Bi-2212/Ag Tapes Prepared by Doctor-Blade Method
We have investigated the relationship between oxygen partial pressure (PO2) during the partial-melting process and superconducting properties for doctor-blade processed Bi-2212/Ag tapes. Tapes were heat-treated at various PO2 value of 0.01–1.00atm. The DTA results for the doctor-blade tapes showed the melting point of the oxide rose with increasing PO2. Correspondingly, the optimum heat-treatment temperature also increased with increasing PO2. The tapes at PO2=L00atm had the highest Jc values of over 105A/cm2 at conditions of 4.2K, 10T, and their a.c. susceptibility showed a sharp transition indicating improved intergrain coupling. Examination of cross sections for tapes melted above 0.20atm PO2 showed the good crystal alignment. From these results, it was concluded that processing at high PO2 was an effective method to obtain good superconducting properties for doctor-blade tapes.
KeywordsDifferential Thermal Analysis Oxygen Partial Pressure Superconducting Property High Oxygen Partial Pressure Differential Thermal Analysis Analysis
Unable to display preview. Download preview PDF.
- 3.N. Tomita, J. Kase, E. Yanagisawa, H. Kitaguchi, H. Kumakura, K. Togano, K. Inoue, and K. Kato, p.777 in “Advances in Superconductivity VII/2”, Springer Verlag, Tokyo (1994).Google Scholar
- 4.M. Okada, K. Tanaka, K. Fukushima, J. Sato, and K. Higashiyama, Proceeding for AHMF ‘95, Tsukuba, Japan, to be published.Google Scholar
- 7.K. Shibutani, T. Hase, Y. Fukumoto, S. Hayashi, Y. Inoue, R. Ogawa, and Y. Kawate, to be published in IEEE Trans, on Appl. Supercond.Google Scholar
- 8.T. Hasegawa, H. Kobayashi, H. Kumakura, and K. Togano, p.719 in “Advances in Superconductivity VII/2”, Springer Verlag, Tokyo(1994).Google Scholar
- 10.W. Zhang and E. E. Hellstrom, to be published in Sci. and Teeh. Google Scholar