Surface Compositional Change of Iron Oxide Porous Nanorods: A Route for Tuning their Magnetic Properties

Abstract
The capability of synthesizing specific nanoparticles (NPs) by varying their shape, size and composition in a controlled fashion represents a typical set of engineering tools that tune the NPs magnetic response via their anisotropy. In particular, variations in NP composition mainly affect the magnetocrystalline anisotropy component, while the different magnetic responses of NPs with isotropic (i.e., spherical) or elongated shapes are mainly caused by changes in their shape anisotropy. In this context, we propose a novel route to obtain monodispersed, partially hollow magnetite nanorods (NRs) by colloidal synthesis, in order to exploit their shape anisotropy to increase the related coercivity; we then modify their composition via a cation exchange (CE) approach. The combination of a synthetic and post-synthetic approach on NRs gave rise to dramatic variations in their magnetic features, with the pores causing an initial magnetic hardening that was further enhanced by the post-synthetic introduction of a manganese oxide shell. Indeed, the coupling of the core and shell ferrimagnetic phases led to even harder magnetic NRs.

Citation
Casu, A., Loche, D., Lentijo-Mozo, S., & Falqui, A. (2020). Surface Compositional Change of Iron Oxide Porous Nanorods: A Route for Tuning their Magnetic Properties. Molecules, 25(5), 1234. doi:10.3390/molecules25051234

Acknowledgements
This research was supported by KAUST Baseline funding to Prof. Andrea Falqui.

Publisher
MDPI AG

Journal
Molecules

DOI
10.3390/molecules25051234

Additional Links
https://www.mdpi.com/1420-3049/25/5/1234

Permanent link to this record