Synthesis of SrAl4O7 via citric acid precursor
Synthesis of SrAl4O7 via citric acid precursor
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柠檬酸前驱体合成 SrAl4O7
DOI：
10.1016/j.matchemphys.2005.05.045
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发表时间：
2006
期刊：
影响因子：
--
通讯作者：
C. Zeng
中科院分区：
文献类型：
--
作者：
Yebin Xu;P. Lu;Guohua Huang;C. Zeng
以柠檬酸为螯合剂、乙二醇为酯化剂，采用Pechini法合成了SrAl4O7。研究了起始溶液的pH值和柠檬酸与总金属阳离子浓度的摩尔比对SrAl4O7形成的影响。提高起始溶液的 pH 值以及柠檬酸与总金属阳离子浓度的摩尔比促进了 SrAl4O7 的形成。当柠檬酸与总金属阳离子浓度的摩尔比为2时，结晶良好，pH为7的前驱体在900℃下2h可合成单相SrAl4O7，而pH为1的前驱体则不能得到单相SrAl4O7。将柠檬酸与总金属阳离子浓度的摩尔比提高至4，在900℃2h也可合成单相SrAl4O7对于pH 7 的前体，它是在1100°C 2 小时获得的。对于pH 1 的前体，它是在1100°C 下获得的。确定了SrAl4O7 的稳定性随时间和温度的变化。我们发现SrAl4O7可以在1400°C下稳定2h，并在1500°C 2h下分解。将单相SrAl4O7粉末在1600℃加热2h，大部分SrAl4O7分解为主要相SrAl12O19和未识别相（主反射在d=3.0149）。使用 DSC、TG、FT-IR 和 XRD 来表征前体和衍生的氧化物粉末。
SrAl4O7was synthesized by Pechini method using citric acid as a chelating agent and ethylene glycol as an esterification agent. The effects of the pH of the starting solutions and the molar ratio of citric acid to total metal cations concentration on the formation of SrAl4O7were investigated. Increasing the pH of the starting solutions and the molar ratio of citric acid to total metal cations concentration promoted the formation of SrAl4O7. When the molar ratio of citric acid to total metal cations concentration was 2, well crystallized, single-phase SrAl4O7was synthesized at 900°C for 2h for the precursor with pH 7, but it could not be obtained for the precursor with pH 1. Increasing the molar ratio of citric acid to total metal cations concentration up to 4, single-phase SrAl4O7was also synthesized at 900°C for 2h for the precursors with pH 7, but it was obtained at 1100°C for 2h for the precursors with pH 1. The stability of SrAl4O7as a function of time and temperature was determined. We found that SrAl4O7can be stable up to 1400°C for 2h and it shows decomposition at 1500°C for 2h. Heating single-phase SrAl4O7powder at 1600°C for 2h, most of SrAl4O7decomposes to SrAl12O19as the major phase and an unidentified phase (main reflection at d=3.0149). DSC, TG, FT-IR and XRD were used to characterize the precursors and the derived oxide powders.