Magnetic Force Microscopy of Micropatterned Clusters of Superparamagnetic Iron Oxide Nanoparticles

Published

June 5, 2025

Author(s)

Kenzington Kottenbrock, Sierra Reis, Gunjan Agarwal, Samuel Oberdick

Abstract

Magnetic force microscopy (MFM) was used to characterize micropatterned clusters of superparamagnetic iron oxide nanoparticles (SPIONs). Top-down lithography was used to create SPION aggregates with well-defined geometries. The micron-scale aggregates exhibited different properties from individual particles and, also, from smaller clusters containing just a few particles. The MFM phase shift from magnetic interactions between the sample and probe tip could be detected at lift heights of several hundred nanometers. The relationship between the MFM phase and lift height decayed more slowly for the micropatterned aggregates compared to the theoretical prediction for single particles. Magnetic interactions between the probe tip and the sample also led to an apparent "ballooning" of the feature size, where the aggregates appeared larger with MFM than their actual physical size. These results can be used to guide emerging applications of MFM, such as detection of SPIONs within biological environments.

Citation

ACS Applied Nano Materials

Volume

8

Pub Type

Journals

Download Paper

https://doi.org/10.1021/acsanm.5c01383

Local Download

Citation

Kottenbrock, K. , Reis, S. , Agarwal, G. and Oberdick, S. (2025), Magnetic Force Microscopy of Micropatterned Clusters of Superparamagnetic Iron Oxide Nanoparticles, ACS Applied Nano Materials, [online], https://doi.org/10.1021/acsanm.5c01383, https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=959356 (Accessed June 29, 2025)