ISSN:
1551-2916
Source:
Blackwell Publishing Journal Backfiles 1879-2005
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
Notes:
The reactions of stoichiometric Y2O3, CuO, and different barium salts (BaCO3, Ba(NO3)2, BaO2, BaCuO2) for forming various compounds in the yttrium—barium—copper—oxygen system (i.e., YBa2Cu3O7–8, BaCuO2, Y2BaCuO5, and Y2Cu2O5) were systematically investigated by thermal analysis and X-ray diffractometry. In a few cases, the relevant activation energies were calculated. The reaction pathway and kinetics were significantly dependent on the physicochemical and thermal stability of the barium precursors, as well as on the crystalline size of the reagent. Binary BaO-CuO phases formed at low temperature (650°-700°3C) when in the presence of easy-to-decompose barium precursors, and then slowly transformed to ternary compounds; in contrast, when barium ions were released at temperatures of 〉900°3C, ternary phases formed directly from the components.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1111/j.1151-2916.1997.tb03057.x
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