Lanthanum copper oxide (La2CuO4) precursors for superconductors were synthesized by acetate/nitrate self-propagating combustion synthesis (SPCS) in the presence of urea at different ratio of O/F. Phase-pure La2CuO4 powder could be obtained by calcining the as-prepared precursors at temperature as low as 600 degreesC. It was demonstrated that the ratio of O/F strongly influenced the composition and morphology of the precursors as well as the samples calcined at various temperatures. We have studied the synthesis conditions, demonstrating the existence of a relationship between the calcination temperature and the calcination time needed to obtain the pure phase. An interesting stereoscopic network structure was observed on the samples synthesized at the ratio of O/F = 0.20, morphology evolution of the samples was also investigated. The emission of H2O as well as CO2 was responsible for the formation of the structure during the calcination process. (C) 2001 Kluwer Academic Publishers.
部门归属
chinese acad sci, inst met res, ceram & composite dept, shenyang 110016, peoples r china.;zhou, yc (reprint author), chinese acad sci, inst met res, ceram & composite dept, 72 wenhua rd, shenyang 110016, peoples r china, peoples r china
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