Bulk Magnetic Properties Arise from Micron‐Sized Supraparticle Interactions and Can be Modified on the Nanoscale

Wolf A, Heinlein M, Kent N, Müssig S, Mandel K (2025)

Publication Type: Journal article

Publication year: 2025

Journal

Small Wiley-VCH Verlag

DOI: 10.1002/smll.202412311

Abstract

Magnetic supraparticles (SPs) can be employed as micron-sized particulate additives in arbitrary objects to serve as ID-tag or recorder of environmental triggers. Combined with magnetic particle spectroscopy (MPS), which enables read-out of the magnetic information in ambient conditions within seconds, magnetic SPs represent a powerful approach to equip materials with information. The encoded information relies on magnetic interactions within the SPs (intra-SP interactions) of chosen nanoparticles (NPs). However, possible magnetic interactions between SPs (inter-SP interactions), that might alter the MPS signal as well, have been neglected so far. Herein, it is elucidated that significant inter-SP interactions exist and that they can be tailored via adjustments in the SP structure, i.e., by defined adjustments of their intra-interaction as revealed by 3D-MuMax simulations and experiments in viscous fluids. Superparamagnetic iron oxide nanoparticle-based SP powders with strong inter-SP interactions exhibit significantly different MPS signals compared to their state after being incorporated into a matrix. Powders with weak inter-SP interactions (achieved by integration of non-magnetic SiO2 nanoparticles) show almost no signal change before and after incorporation. Both extremes of inter-SP interactions can be beneficial for various application scenarios and can be tailored on the nano-scale due to the interdependency of intra- and inter-SP interactions.

Authors with CRIS profile

Andreas Wolf Professur für Anorganische Chemie Markus Heinlein Professur für Anorganische Chemie Stephan Müssig Professur für Anorganische Chemie Karl Mandel Professur für Anorganische Chemie

Involved external institutions

Massachusetts Institute of Technology (MIT) US United States (USA) (US)

How to cite

APA:

Wolf, A., Heinlein, M., Kent, N., Müssig, S., & Mandel, K. (2025). Bulk Magnetic Properties Arise from Micron‐Sized Supraparticle Interactions and Can be Modified on the Nanoscale. Small. https://doi.org/10.1002/smll.202412311

MLA:

Wolf, Andreas, et al. "Bulk Magnetic Properties Arise from Micron‐Sized Supraparticle Interactions and Can be Modified on the Nanoscale." Small (2025).

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