Abstract
We demonstrate a magneto-optic technique to measure Brownian relaxation of magnetic nanoparticles suspended in liquids. We used AC susceptibility data as a function of frequency of the applied AC magnetic field to verify that the results agree with those obtained via a conventional inductive detection technique. However, compared with a commercial AC susceptometer using the conventional detection scheme, our magneto-optic setup is able to detect a density of nanoparticles at least three orders smaller. This technique has the potential of being used as a sensor for magnetic nanoparticles such as in local temperature, viscoelasticity, or molecular-binding measurements.
| Original language | English |
|---|---|
| Pages (from-to) | 91-95 |
| Number of pages | 5 |
| Journal | Journal of Magnetism and Magnetic Materials |
| Volume | 320 |
| Issue number | 3-4 |
| DOIs | |
| State | Published - Feb 2008 |
Bibliographical note
Funding Information:The authors acknowledge the helpful discussions with F. Fradin. This work was supported by the US Department of Energy, Basic Energy Sciences, under Contract No. DE-AC02-06CH11357, and by NERCE 14898830458, the Salomon Award and the Frontier Research Award from Brown University.
Keywords
- AC susceptibility
- Biosensing
- Brownian relaxation
- Magnetic nanoparticle
- Magneto-optic