Tuning the surface states of Fe3O4 nanoparticles for enhanced magnetic anisotropy and induction efficacy
No Thumbnail Available
Date
2025-09-10
Journal Title
Journal ISSN
Volume Title
Publisher
American Chemical Society
Abstract
Magnetite (Fe3O4) nanoparticles are crucial for biomedical applications, including magnetic hyperthermia, targeted drug delivery, and MRI contrast enhancement due to their biocompatibility and unique physicochemical properties. Here, we investigate how surface states influence their induction performance. Heat treatment removes surface water and FeOOH, forming a γ-Fe2O3 shell, as confirmed by synchrotron powder diffraction, thermogravimetric analysis, X-ray photoelectron spectroscopy, X-ray absorption spectroscopy, and time-of-flight inelastic neutron spectroscopy. AC magnetic susceptibility measurements reveal that this surface modification enhances magnetic anisotropy and reduces the spin relaxation time, leading to a 140% increase in the specific absorption rate. Additionally, the increased anisotropy suppresses the low-temperature clustered spin-glass transition and raises the blocking temperature. These findings highlight surface-state engineering as a powerful approach to optimizing Fe3O4 nanoparticles for biomedical applications. © 2025 American Chemical Society.
Description
Keywords
Iron, Nanoparticles, Anisotropy, Surface waters, Heat treatments, Magnetite, Synchrotrons, Neutron spectroscopy
Citation
Portwin, K. A., Galaviz, P., Li, X., Hao, C., Smillie, L. A., You, M., Stamper, C., Mole, R. A., Yu, D., Rule, K. C., Cortie, D. L., & Cheng, Z. (2025). Tuning the surface states of Fe3O4 nanoparticles for enhanced magnetic anisotropy and induction efficacy. Chemistry of Materials, 37(18), 7347–7358. doi:10.1021/acs.chemmater.5c01654