Synthesis and characterization of iron oxide nanoparticles grown via a non-conventional chemical method using an external magnetic field

Abstract Iron oxide nanoparticles (NPs) were synthesized at room temperature, using a method based on a chemical reaction of iron filings, white vinegar, hydrogen peroxide, and ammonium hydroxide, in the presence of an external magnetic field (EXMF) of 1200 G. X-ray diffraction (XRD) analysis indicates that magnetite (Fe 3 O 4 ) is the most predominant phase, with lepidocrocite (γ-FeO(OH)) in smaller proportion. The shape and average particle size is altered by the application of a magnetic field during NPs synthesis. The average size of crystallite calculated with Scherrer’s equation were 30.30 nm without EXMF and 18.37 nm with EXMF. Using electron microscopy techniques (SEM, TEM), NPs with regular shapes were identified when the EXMF was applied. Meanwhile, irregular shapes were observed when the EXMF was not applied. Some NPs with nanoflake shapes and the crystalline phases γ-FeO(OH) were also identified. High-resolution transmission electron microscopy (HRTEM) showed that the NPs with regular shapes are of Fe 3 O 4 .