Abstract
Heat dissipation characteristics and magnetic properties of iron oxide nanoparticles (IOPs) synthesized by co-precipitation and thermal decomposition are reported. IOPs were successfully synthesized by thermally decomposing iron pentacarbonyl in an atmospheric condition. According to transmission electron microscopy, the particle diameter varied between 3.0 and 12.2 nm depending on the concentration of oleic acid and reaction time. On the other hand, coprecipitated IOPs with an average diameter of 10.2 nm were synthesized by introducing ammonia solution to the aqueous solution of iron sulfate and iron chloride mixture. The heat dissipation characteristics of the isoparaffin dispersion of IOPs were measured by exposing a magnetic field strength and frequency of 3.2 kA/m and 600 kHz respectively. For a specific time, the coprecipitated particles with an average diameter of 10.2 nm exhibited a temperature rise of 77 K, whereas the temperature rise exhibited by particles synthesized by thermal decomposition with an average diameter of 11.3 nm was 14 K. On the other hand, particles with an average diameter of 3.0 nm did not generate significant heat. The magnetic property of the samples, especially the temperature at which the magnetic susceptibility becomes maximum (blocking temperature) was measured using superconducting quantum interference device. The results suggested that the sample with higher blocking temperature generated more heat.
