Synthesis of Nanoscale Nd-Doped Ceria Via Urea-Formaldehyde Combustion Method

Nanocrystalline neodymium-doped ceria solid solutions with Nd³⁺ concentrations varying from 4 to 20 mol pct have been synthesized by gel combustion method, using urea-formaldehyde as fuel for Nd doping. The combustion reaction is explained through differential scanning calorimetry (DSC)-differential thermogravimetric analysis (TGA), whereas the synthesized materials are characterized through X-ray diffractometry (XRD), field-emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM). The phase obtained from the exothermic reaction contains Nd-substituted CeO₂. The deviation of the lattice parameter from Vegard’s law and the decrease in crystallite size with dopant concentration has been explained. The as-synthesized particles are largely nanoporous single crystallites, existing in loosely held spherical-shaped agglomerates. The size of the agglomerates increases with increasing dopant content. High-resolution TEM (HRTEM) reveals the fact that the unit cells are strained.