Nguyen Minh Dang, Deng Liangzi, Lee Jong Moon, Resendez Karla M, Fuller Maggie, Hoijang Supawitch, Robles-Hernandez Francisco, Chu Ching-Wu, Litvinov Dmitri, Hadjiev Viktor G, Xu Shoujun, Phan Manh-Huong, Lee T Randall
Department of Chemistry and the Texas Center for Superconductivity, University of Houston, Houston, TX, 77204-5003, USA.
Department of Physics and the Texas Center for Superconductivity, University of Houston, Houston, TX, 77204-5003, USA.
Small. 2024 Oct;20(43):e2402940. doi: 10.1002/smll.202402940. Epub 2024 Jul 14.
Iron oxide nanoparticles (IONPs) are widely used for biomedical applications due to their unique magnetic properties and biocompatibility. However, the controlled synthesis of IONPs with tunable particle sizes and crystallite/grain sizes to achieve desired magnetic functionalities across single-domain and multi-domain size ranges remains an important challenge. Here, a facile synthetic method is used to produce iron oxide nanospheres (IONSs) with controllable size and crystallinity for magnetic tunability. First, highly crystalline FeO IONSs (crystallite sizes above 24 nm) having an average diameter of 50 to 400 nm are synthesized with enhanced ferrimagnetic properties. The magnetic properties of these highly crystalline IONSs are comparable to those of their nanocube counterparts, which typically possess superior magnetic properties. Second, the crystallite size can be widely tuned from 37 to 10 nm while maintaining the overall particle diameter, thereby allowing precise manipulation from the ferrimagnetic to the superparamagnetic state. In addition, demonstrations of reaction scale-up and the proposed growth mechanism of the IONSs are presented. This study highlights the pivotal role of crystal size in controlling the magnetic properties of IONSs and offers a viable means to produce IONSs with magnetic properties desirable for wider applications in sensors, electronics, energy, environmental remediation, and biomedicine.
氧化铁纳米颗粒（IONPs）因其独特的磁性和生物相容性而被广泛应用于生物医学领域。然而，可控合成具有可调粒径和微晶/晶粒尺寸的IONPs，以在单畴和多畴尺寸范围内实现所需的磁功能，仍然是一项重大挑战。在此，我们采用一种简便的合成方法来制备具有可控尺寸和结晶度以实现磁可调性的氧化铁纳米球（IONSs）。首先，合成了平均直径为50至400 nm、具有增强亚铁磁性的高结晶度FeO IONSs（微晶尺寸大于24 nm）。这些高结晶度IONSs的磁性能与其纳米立方体对应物相当，后者通常具有优异的磁性能。其次，在保持整体粒径的同时，微晶尺寸可在37至10 nm范围内广泛调节，从而实现从亚铁磁性到超顺磁性状态的精确调控。此外，还展示了反应放大以及所提出的IONSs生长机制。本研究突出了晶体尺寸在控制IONSs磁性能方面的关键作用，并提供了一种可行的方法来制备具有所需磁性能的IONSs，以便在传感器、电子、能源、环境修复和生物医学等更广泛的应用中使用。
