Abstract
The thermal decomposition of erbium oxalate hydrate (Er
2(C
2O
4)
3·6H
2O) till 900°C, in air and nitrogen, is investigated by nonisothermal gravimetry and differential thermal analyses. The activation energy (Δ
E) is determined for each thermal decomposition step. The gaseous decomposition products are identified by infrared (IR)-spectroscopy. Intermediate and final solid products are characterized by IR-spectroscopy and X-ray diffraction (XRD). The results indicate that, in air atmosphere, following a stepwise dehydration at 90–370°C, the anhydrous product was noncrystalline and thermally unstable. An oxycarbonate Er
2O
2CO
3 is obtained at 450°C which decomposes near 600°C into crystalline Er
2O
3. The atmosphere has no affect on the decomposition pathway. The oxide proportion and crystallinity improved on increasing the temperature to 800°C. The volatile decomposition products were water vapor and carbon oxides.