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采用TG-DTA法研究了化学共沉淀法制备BiSrCaCuO超导体材料的热分解过程以及热重反应。实验证明,该种材料的草酸盐化合物在高温过程中的热分解变化有三个过程,一是结晶水分解(吸热反应),二是CO分解(放热反应),三是CO_2分解(吸热反应)。对热重反应的研究确认了草酸盐分子式分别为CaC_2O_4·H_2O,SrC_2O_4·2H_2O,2CuC_2O_4·H_2O,2Bi_2(C_2O_4)_3·15H_2O。比较了BiSrCaCu的单质化合物和按一定比例组成的草酸盐混合物,可以看到草酸盐混合物的热分解过程是一种综合反应,与单质化合物的热分解变化有一定差异,且三种过程的分解温度有提前的趋势,草酸盐化合物已大体上分解成氧化物体系。
The thermal decomposition reaction and thermogravimetric reaction of BiSrCaCuO superconductor prepared by chemical coprecipitation method were studied by TG-DTA. Experiments show that there are three processes for thermal decomposition of the oxalate compounds in the high temperature process. One is the crystallization of water (endothermic reaction), the other is the decomposition of CO (exothermic reaction) and the third is the decomposition of CO 2 Thermal reaction). The thermogravimetric study confirmed that the oxalate formulas were CaC_2O_4 · H_2O, SrC_2O_4 · 2H_2O, 2CuC_2O_4 · H_2O and 2Bi_2 (C_2O_4) _3 · 15H_2O, respectively. Comparing the elemental composition of BiSrCaCu and the mixture of oxalate in a certain proportion, it can be seen that the thermal decomposition process of the oxalate mixture is a comprehensive reaction, which is different from the thermal decomposition of elemental compounds. The three processes Decomposition temperature has an early trend, oxalate compounds have been largely decomposed into oxide systems.