An in-depth in situ IR study of the thermal decomposition of yttrium trifluoroacetate hydrate
An in-depth in situ IR study of the thermal decomposition of yttrium trifluoroacetate hydrate
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DOI：
10.1007/s10973-011-1772-6
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发表时间：
2012-02-01
影响因子：
4.4
通讯作者：
Glowacki, B. A.
中科院分区：
文献类型：
--
作者：
Mosiadz, M.;Juda, K. L.;Glowacki, B. A.
对Y（CF 3COO）（3）中心点nH（2）O在高达1，000 A ℃的温度下，在流动的纯Ar、O-2和饱和水蒸气的O-2中的热解进行了广泛的分析。直接观察到HF的形成，并推断在三氟乙酸盐分解过程中存在：CF2双自由基。高分辨率热重法，差示扫描量热法，X-射线衍射法和扫描电子显微镜表明，在267摄氏度下发生的无水盐的放热的一阶段分解，形成YF 3。傅立叶变换红外光谱法确定（CF 3CO）（2）O，CF 3COF，COF 2，CO2和CO作为主要的挥发性物质;并揭示了水对反应的影响，释放气态CF 3COOH，CHF 3，HF和SiF 4（与玻璃或石英成分反应）。NO2和N2 O的释放表明在起始材料中存在痕量的CH 3 NO2。热重分析和X射线衍射表明，氟化物的缓慢水解发生在630和655 A度之间，形成Y2 O3，YOF，Y 7 O 6 F9和YF 3的混合物。的分解和水解温度显着低于以前报道的，这对溶胶-凝胶工艺的影响。
The pyrolysis of Y(CF3COO)(3)center dot nH(2)O at temperatures up to 1,000 A degrees C, under flowing pure Ar, O-2 and O-2 saturated with water vapour, was extensively analysed. The formation of HF is observed directly and the existence of a :CF2 diradical is inferred during a trifluoroacetic acid salt decomposition. High resolution thermogravimetry, differential scanning calorimetry, X-ray diffractometry and scanning electron microscopy indicated that the exothermic one-stage decomposition of the anhydrate salt occurs at 267 A degrees C, forming YF3. Fourier transform infrared spectroscopy identified (CF3CO)(2)O, CF3COF, COF2, CO2 and CO as the principal volatile species; and revealed the influence of water on the reactions liberating gaseous CF3COOH, CHF3, HF, and SiF4 (from reactions with glass or quartz components). NO2 and N2O evolution suggested that traces of CH3NO2 were present in the starting material. Thermogravimetry and X-ray diffractometry indicated that the slow hydrolysis of the fluoride occurs between 630 and 655 A degrees C, forming a mixture of Y2O3, YOF, Y7O6F9, and YF3. The decomposition and hydrolysis temperatures are significantly lower than previously reported, which has implications for sol-gel processing.