Combustion synthesis, structural and optical properties of Nd-doped ceria nanoparticles

A solution combustion approach was used in the preparation of nanosize Ce0.9Nd0.1O1.95 using mixture of citric acid as a fuel with corresponding metal nitrates of cerium and neodymium. The prepared nanoparticles were ground into fine powders and calcined at 700 °C in air for 2 h. The calcined Ce0.9Nd0.1O1.95 powders were made into cylindrical bodies by uni-axial pressing, and subsequently sintered at 1200 °C for 6 h. The nanopowders were characterized by X-ray diffractometry (XRD), Fourier transform infrared spectrometry (FTIR), Raman spectrometry, Scanning electron microscopy (SEM) and Transmission electron microscopy (TEM). The XRD results revealed that the Ce0.9Nd0.1O1.95 crystallizes as cubic fluorite structure similar to pure ceria. The FTIR spectrum shows the lower frequency bands at 555 cm–1 corresponds to the stretching frequencies of metal-oxygen bonds. Raman active mode was observed at 468 cm–1 and the existence of oxygen vacancies were confirmed from the weaker absorption region 513–650 cm–1. The average particle size of the Nd-doped ceria was found to be in the range of 10–25 nm from the TEM results, which is in good agreement with the particle sizes calculated from X-ray peak broadening method.