Thermal decomposition of lutetium propionate

The thermal decomposition of lutetium(III) propionate monohydrate (Lu(C2H5CO2)3·H2O) in argon was studied by means of thermogravimetry, differential thermal analysis, IR-spectroscopy and X-ray diffraction. Dehydration takes place around 90 °C. It is followed by the decomposition of the anhydrous propionate to Lu2O2CO3 with evolution of CO2 and 3-pentanone (C2H5COC2H5) between 300 °C and 400 °C. The further decomposition of Lu2O2CO3 to Lu2O3 is characterized by an intermediate constant mass plateau corresponding to a Lu2O2.5(CO3)0.5 overall composition and extending from approximately 550 °C to 720 °C. Full conversion to Lu2O3 is achieved at about 1000 °C. Whereas the temperatures and solid reaction products of the first two decomposition steps are similar to those previously reported for the thermal decomposition of lanthanum(III) propionate monohydrate, the final decomposition of the oxycarbonate to the rare-earth oxide proceeds in a different way, which is here reminiscent of the thermal decomposition path of Lu(C3H5O2)·2CO(NH2)2·2H2O.