Gd2O3∶Tb3+ luminescent nanoparticles were prepared by the thermal decomposition of the nanosized oxlate prepared in the reverse microemulsions based on triton X-100/n-hexyl alcohol, n-octane, and water. From TG-DTA, XRD and FTIR analyses, the mechanism of thermal decomposition of the nanosized oxalate precursor is suggested as follows: Gd2(C2O4)3·10H2O → Gd2(C2O4)3 + 10H2O, Gd2(C2O4)3 → Gd2O2(CO3) + 3CO +2CO2, Gd2O2(CO3) → Gd2O3 + CO2. The kinetic parameters of thermal decomposition reaction-activation energy E of stage 2 and 3 are 194.6 kJ·mol-1, 110.9 kJ·mol-1, respectively, using Ozawa method. And the reaction order n is 2.9 and 0.43, respectively, according to the TG curves.
