Effect of pre-annealing temperature and atmosphere on the microstructure and transport property of Bi-2223/Ag tapes

• Published in: IEEE transactions on applied superconductivity Vol. 15; no. 2; pp. 2458 - 2461
• Main Authors: Jiang, C.H., Kumakura, H., Koizumi, T.
• Format: Journal Article Conference Proceeding
• Language: English
• Published: New York, NY IEEE 01.06.2005; Institute of Electrical and Electronics Engineers; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Annealing; ANNEALING PROCESSES; ANNEALING TEMPERATURE; Applied sciences; Argon; Assembly; Atmosphere; Bi-2223/Ag tapes; Electrical engineering. Electrical power engineering; Electronics; Evolution; Exact sciences and technology; Heat treatment; Lead; Materials; Microstructure; MICROSTRUCTURES; Oxidation; Powders; pre-annealing; PROPERTIES; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Silver; Superconducting devices; Superconducting tapes; SUPERCONDUCTIVITY; SUPERCONDUCTORS; Surface layer; TAPE; Temperature; Texture; TEXTURES; Transport properties; Averaging method; Annealing; Heat treatment; Transport properties; Superconducting tapes; Annealing temperature; pre-annealing; Bi-2223/Ag tapes; Microstructure; Texture; Comparative study; High temperature superconductor
• ISSN: 1051-8223; 1558-2515
• DOI: 10.1109/TASC.2005.847479

The phase assemblage and Bi-2212 texture in Bi-2223/Ag tapes before the heat treatment were varied by pre-annealing the tapes at different temperatures and in pure Ar or air for 10 h. Then all the tapes were isothermally heat treated at 840/spl deg/C in air for 4 cycles with intermediate pressings. The J/sub c/ of the samples pre-annealed in pure Ar were lowered no matter which annealing temperature was used. The best J/sub c/ was obtained in the samples pre-annealed at 800/spl deg/C in air, which was in an average value of 21.7 kA cm/sup -2/, being increased by 25% compared with that of the unannealed tapes (17.3 kA cm/sup -2/). The transport properties of various pre-annealed samples were correlated to the phase evolutions, growth and pre-alignment of Bi-2212 grains during pre-annealing.