Optical and magnetic properties of elliptical hematite (α-Fe2O3) nanoparticles coated with uniform continuous layers of silica of different thickness

Elliptical-type alpha-Fe2O3 nanoparticles with/without silica shell have been prepared. The core particles were coated with uniform continuous layers of silica of two different thicknesses by hydrolysis of TEOS. The obtained HCP structure elliptical alpha-Fe2O3 nanoparticles with similar to 240 nm length and 100 nm width is polycrystalline in nature. The thicknesses of SiO2 shell coated on (alpha-Fe2O3 are about 55 and 30 nm, respectively. The optical and magnetic properties of these nanoparticles have been investigated. (c) 2007 Elsevier B.V. All rights reserved.