Auto-Combustion Synthesis of Nanocrystalline FeCrO3

Abstract

Nanocrystalline FeCrO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> with particle size of about 83-123 nm was directly synthesized by sol-gel auto- combustion method 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 FeCrO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> dried gel derived from glycine and nitrate sol exhibits self-propagating combustion at room temperature once it is ignited in air. After auto- combustion, the desired nanocrystalline FeCrO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> was acquired and no further calcination was needed. The auto- combustion was considered as a heat-induced exothermic oxidation-reduction reaction between nitrate ions and carboxyl group. The synthesized powder was characterized by X-ray diffraction (XRD), thermogravimetric and differential thermal analysis (TG/DTA), IR spectroscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM).