Magnetic properties of spindle-type iron fine particles obtained from hematite

Spindle-type iron fine particles have been prepared by reduction of silica-coated-hematite particles. Hydrogen reduction of the coated-hematite cores yielded uniform spindle-type iron particles, which were stabilized by surface oxidation. Narrow particle distributions are observed from TEM measurements. X-ray, Mössbauer and magnetization data are in agreement with the presence of nanosized α-Fe particles, having surface layer of spinel structure oxide. Mössbauer spectra show that the oxide surface is superparamagnetic at room temperature. © 2001 Elsevier Science B.V. All rights reserved.

Keywords

Fine particles, Iron particles, Magnetic pigments, Magnetic recording media, Hematite particles, Hydrogen reduction, Iron-fines, Magnetization data, Mossbauer, Nano-sized, Oxide surface, Particle distributions, Room temperature, Silica-Coated, Spinel structure, Superparamagnetics, Surface layers, Surface oxidations, TEM, Hematite, Iron ores, Magnetic devices, Magnetic properties, Magnetic recording, Magnetism, Molybdenum oxide, Reaction kinetics, Silica, Superparamagnetism, Surface structure, Magnetic bubbles