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Field-dependent dynamic responses from dilute magnetic nanoparticle dispersions
Jeppe Fock1, Christoph Balceris, Rocio Costo
1Department of Micro- and Nanotechnology, DTU Nanotech, Bldg. 345B, Technical University of Denmark, DK-2800 Kongens Lyngby, Denmark. jepf@nanotech.dtu.dk Mikkel.Hansen@nanotech.dtu.dk.
Nanoscale
|January 12, 2018
Summary
Optomagnetic (OM) and AC susceptibility (ACS) measurements reveal size and magnetic moment distributions in magnetic nanoparticles (MNPs). MNP magnetic moment scales with the square root of hydrodynamic size, crucial for applications like magnetic hyperthermia.
Area of Science:
- Materials Science
- Nanotechnology
- Magnetism
Background:
- Magnetic nanoparticles (MNPs) are vital for applications like magnetic hyperthermia and MRI.
- Particle size and magnetic moment critically influence MNP dispersion performance.
- Understanding MNP behavior beyond linear response is key for advanced applications.
Purpose of the Study:
- To present and demonstrate optomagnetic (OM) and AC susceptibility (ACS) measurements for MNP characterization.
- To obtain size and magnetic moment distributions and their correlations.
- To investigate the influence of induced magnetic moments and shape anisotropy.
Main Methods:
- Solving Fokker-Planck equations for MNPs with permanent and induced magnetic moments.
- Developing analytical approximations for ACS and OM signals at varying field strengths.
- Fitting ACS and OM measurements on multi-core particle systems.
Main Results:
- Obtained size and magnetic moment distributions, including correlations.
- Demonstrated that MNP magnetic moment is proportional to the square root of hydrodynamic size.
- Characterized multi-core particle systems using OM and ACS data.
Conclusions:
- OM and ACS are powerful tools for MNP characterization, providing detailed size and magnetic moment information.
- The correlation between size and magnetic moment offers insights into particle morphology.
- The findings are crucial for optimizing MNPs in diverse technological applications.
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