A simple way to prepare nanosized LaFeO3 powders at room temperature

Nanosized LaFeO3 powders of 30 nm particle size were directly prepared by sol-gel auto-combustion at room temperature. The overall process involves three steps: formation of homogeneous sol; formation of dried gel, and combustion of the dried gel. Experiments revealed that LaFeO3 dried gel derived from citrate and nitrate sol exhibits self-propagating combustion at room temperature once it is ignited in air. After auto-combustion, the gel directly transforms into nanosized LaFeO3 particles. The autocombustion was considered as a heat-induced exothermic oxidation-reduction reaction between nitrate ions and carboxyl group. Differential thermal analysis-thermogravimetry (DTA-TG) was used to study the decomposition of the precursor. The structure of the nanosized LaFeO3 powders was characterized by X-ray diffraction (XRD). (C) 2002 Elsevier Science Ltd and Techna S.r.l. All rights reserved.