Simulation and experimental study of cuboid and spherical magnetic Fe3O4 nanoparticles prepared with NaOH and NH4OH

• Published in: Applied physics. A, Materials science & processing Materials science & processing, 2023-12, Vol.129 (12), Article 851
• Main Author: Harris, R. A.
• Format: Article
• Language: English
• Subjects: Ammonium hydroxide; Applied physics; Characterization and Evaluation of Materials; Chemical synthesis; Condensed Matter Physics; Hydroxyl groups; Iron oxides; Machines; Magnetic properties; Manufacturing; Materials science; Molecular dynamics; Morphology; Nanoparticles; Nanotechnology; Optical and Electronic Materials; Physics; Physics and Astronomy; Processes; Stabilizers (agents); Surfaces and Interfaces; Thin Films
• ISSN: 0947-8396; 1432-0630
• DOI: 10.1007/s00339-023-07128-5

A molecular dynamics study is done on cuboid and spherical Fe 3 O 4 magnetic nanoparticles (NPs) to investigate qualitatively the influence of the molecules NH 4 OH and NaOH on their binding energy. This is done to determine the stability and therefore likely shape (morphology) and size of the synthesized NPs when these molecules are used as stabilizing agents. We show through molecular dynamics (MD) that small, spherical NPs synthesized with NH 4 OH, and large, cuboid NPs synthesized with NaOH, are the most stable NP systems and therefore the most likely outcome of a synthesis experiment. Furthermore, we synthesize these systems under similar conditions as predicted and find that when NaOH is used large (29 ± 2 nm), cuboid NPs are formed and when NH 4 OH is used, small (11 nm ± 2 nm), spherical NPs are formed. The role of pH is further investigated using the desorbed (and unadsorbed hydroxyl groups) as indicators of pH. The magnetic NPs are then synthesized via the co-precipitation method and the resulting NPs characterized for crystallinity, morphology, size and magnetic properties.