Nanocrystalline Nd2O3: Preparation, phase evolution, and kinetics of thermal decomposition of precursor

Nd2O3 was synthesized by calcining Nd2(C2O4)3·10H2O in air. The precursor and its calcined products were characterized by thermogravimetry and differential scanning calorimetry, Fourier transform infrared spectroscopy, X-ray powder diffraction, and scanning electron microscopy. The results showed that high-crystallized Nd2O3 with hexagonal structure was obtained when the precursor was calcined at 1223 K in air for 2 h. The crystallite size of Nd2O3 synthesized at 1223 K for 2 h was about 48 nm. The thermal decomposition of the precursor in air experienced three steps, which are first, the dehydration of 10 crystal water molecules; then, the decomposition of Nd2(C2O4)3 into Nd2O2CO3; and last, the decomposition of Nd2O2CO3 into hexagonal Nd2O3. Based on the KAS equation, the values of the activation energies associated with the thermal decomposition of Nd2(C2O4)3∙10H2O were determined.