An in-depth in situ IR study of the thermal decomposition of yttrium trifluoroacetate hydrate.

The pyrolysis of Y(CFCOO)· nHO at temperatures up to 1,000 °C, under flowing pure Ar, O and O saturated with water vapour, was extensively analysed. The formation of HF is observed directly and the existence of a :CF 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 °C, forming YF. Fourier transform infrared spectroscopy identified (CFCO)O, CFCOF, COF, CO and CO as the principal volatile species; and revealed the influence of water on the reactions liberating gaseous CFCOOH, CHF, HF, and SiF (from reactions with glass or quartz components). NO and NO evolution suggested that traces of CHNO were present in the starting material. Thermogravimetry and X-ray diffractometry indicated that the slow hydrolysis of the fluoride occurs between 630 and 655 °C, forming a mixture of YO, YOF, YOF, and YF. The decomposition and hydrolysis temperatures are significantly lower than previously reported, which has implications for sol-gel processing. [ABSTRACT FROM AUTHOR]