Ultrafine ceria powders via glycine-nitrate combustion

The ultrafine ceria powders have been synthesized by the combustion technique using glycine as a fuel and nitrate as an oxidizer. The auto-ignition (at approximate to 200 degreesC) of the viscous liquids containing cerium nitrate and glycine resulted in voluminous ceria powders. An interpretation based on an adiabatic flame temperature, for different fuel-to-oxidant ratios, has been proposed for the nature of combustion and its correlation with the powder characteristics. The combustion synthesized ceria powders have been characterized by XRD, HRTEM, surface area analysis, and sinterability. Specific surface area and primary crystallite size of the ceria powder obtained through fuel-deficient precursor was found to be approximate to 75 m(2)/g and 2.5-12 nm, respectively. The powder, when cold pressed and sintered in air at 1250 degreesC for 1 h, attained the sintered density approximate to 94% of its theoretical density, with submicron grain size. (C) 2001 Elsevier Science Ltd. All rights reserved.