Microstructure and properties of Bi-Sr-Ca-Cu-O with additions of nanometer-scale alumina
- Resource Type
- Periodical
- Authors
- Goretta, K.C.; Cuber, M.M.; Feng, L.R.; Fisher, B.L.; Jiang, M.; Lanagan, M.T.; Balachandran, U.; Xu, Y.; Xu, M.
- Source
- IEEE Transactions on Applied Superconductivity IEEE Trans. Appl. Supercond. Applied Superconductivity, IEEE Transactions on. 9(2):1896-1899 Jun, 1999
- Subject
- Fields, Waves and Electromagnetics
Engineered Materials, Dielectrics and Plasmas
Microstructure
Powders
High temperature superconductors
US Department of Energy
Scanning electron microscopy
Magnetic hysteresis
X-ray diffraction
Transmission electron microscopy
Heating
Heat treatment
- Language
- ISSN
- 1051-8223
1558-2515
2378-7074
Al/sub 2/O/sub 3/ particles /spl ap/30 nm in size were added to Bi/sub 2/Sr/sub 2/CaCu/sub 2/O/sub x/ in a 1:4 molar ratio. For comparison, 0.3- and /spl ap/3-/spl mu/m Al/sub 2/O/sub 3/ particles were added to separate batches. All of the materials were partial-melt processed. The Al/sub 2/O/sub 3/ reacted during melting to form stable compounds, primarily of approximate composition (Sr,Ca)/sub 2/AlO/sub 4/. All additions caused slight decreases in the T/sub c/ and melting point of the Bi/sub 2/Sr/sub 2/CaCu/sub 2/O/sub x/. The submicrometer Al/sub 2/O/sub 3/ additions induced large expansions in magnetic-hysteresis width at 6 K. Electron microscopy examination strongly suggested that the hysteresis expansion was related to alloying of the Bi/sub 2/Sr/sub 2/CaCu/sub 2/O/sub x/ matrix rather than to pinning by volume defects.