Abstract

This study was focused on the optimization of low-pressure ultrasonic spraying process for synthesis of pure gamma-Fe_2O_3 nanoparticles. As process variables, pressure in the reactor, precursor concentration, and reaction temperature were changed in order to control the chemical and microstructural properties of iron oxide nanoparticles including crystal phase, mean particle size and particle size distribution. X-ray diffraction (XRD) and transmission electron microscopy (TEM) studies revealed that pure gamma-Fe_2O_3 nanoparticles with narrow particle size distribution of 5-15 nm were successfully synthesized from iron pentacarbonyl (Fe(CO)_5) in hexane under 30 mbar with precursor concentrations of 0.1M and 0.2M, at temperatures over 800°C. Also magnetic properties, coercivity (H_c) and saturation magnetization (M_s) were reported in terms of the microstructure of particles based on the results from vibration sampling magnetometer (VSM).

• Keywords: gamma-Fe_2O_3 nanoparticles;Low-pressure ultrasonic spraying;Iron pentacarbonyl;Ferrimagnetism;