The size and strain effects on the Raman spectra of Ce 1− xNd xO 2− δ (0≤ x≤0.25) nanopowders

Abstract

Ultrafine Ce 1− x Nd x O 2− δ ( x=0–0.25) powders were synthesized by self-propagating room temperature synthesis. Raman spectra were measured at room temperature in the 300–700 cm −1 spectral range. The shift and asymmetric broadening of the Raman F 2g mode at about 454 cm −1 in pure and doped ceria samples could be explained with combined size and inhomogenous strain effects. Increased concentration of O 2− vacancies with doping is followed by an appearance of new Raman feature at about 545 cm −1.