Investigation of size dependency on lattice strain of nanoceria particles synthesised by wet chemical methods

Abstract

An investigation of the influence of synthesis conditions on the crystallite size, lattice parameter and lattice strain of ceriumdioxide nanoparticles synthesised by coprecipitation and sol-gel processes is presented. The effect of initial precursors, precipitation and calcination temperatures, aging time and molar concentrations of precursor solution on particle size and lattice parameter has been studied. The physicochemical characterisation was performed using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy-dispersive X-ray analysis (EDX), and thermal analysis (TG-DTA). XRD profile indicates the presence of cubic fluorite-structured nanoce-ria particles. The average crystallite size of the samples determined by Debye-Scherrer formula ranges from 4.2 to 36.9 nm. Lattice parameters vary from 5.37 to 5.44 A ˚. Lattice strain of the samples was analysed using William-son-Hall analysis since these relate to imperfections and distortions in the crystal structure. It is found that ceria reduces strain by lattice expansion which is pronounced in lower dimensions.