Simple Hydrothermal Synthesis and Morphological Study of Magnetic Nanoparticles

Abstract

Magnetite (Fe3O4) nanoparticles were synthesized using FeCl3•6H2O or FeCl2•4H2O with 5 or 8 mmol concentration and 3 or 5 h incubation time with the constant pH (7.5) by simple hydrothermal decomposition and then transferred them into maghemite (γ-Fe2O3) and hematite (α-Fe2O3). Precisely, the objectives of the study were to evaluate the influences of salt type, its concentration and incubation time on the morphology of the as-synthesized magnetic nanoparticles. Synthesized nanoparticles were characterized by means of XRD, FE-SEM, TEM, UV-Vis absorption (reflectance) spectra and magnetic hysteresis loops by superconducting quantum interference device (SQUID), without any size sorting. In case of iron hexahydrate (FeCl3•6H2O), 5 mmol salt concentration along with 5 h incubation period results in homogeneous spherical-shaped particles. On the other hand, the same salt but 8 mmol concentration and 3 h incubation period produced heterogeneous spherical-shaped particles with bigger particle sizes. In case of iron tetrahydrate (FeCl2•4H2O) almost neck-structured heterogeneous particles were obtained by using both types of salt concentrations and incubation period (5 or 8 mmol and 5 or 3 h). Finally, our study revealed that in both type of salts, increased concentration and decreased incubation period result in increased particles size.
Keywords: Magnetic materials, Spherical-shaped, Neck-structured, Hysteresis loops, Salt, Hyperthermia