Abstract
We demonstrate a novel method allowing the study of the magnetic state dynamics of a single nanoparticle by means of electron transport measurements. Elliptical 550 nm×240 nm permalloy nanoparticles are wired with non-magnetic leads for magnetotransport measurements in the presence of a radio frequency (RF) field. Their resistance exhibits sharp jumps due to the anisotropic magnetoresistance (AMR) even at room temperature. An RF field induces DC voltage across the nanoparticle, which can be partially depleted at a certain RF frequency when a magnetic vortex core resonance is present. An application of an additional DC magnetic field eliminates the vortex and reinstates the unperturbed DC voltage level. The vortex core resonance frequencies are found and the smallest resonance widths are estimated to be less than 6 MHz.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 47-52 |
| Number of pages | 6 |
| Journal | Journal of Magnetism and Magnetic Materials |
| Volume | 320 |
| Issue number | 1-2 |
| DOIs | |
| State | Published - Jan 2008 |
Funding
The work was supported by the Office of Research at Northwestern University. The authors are thankful to Prof. Ketterson for providing the RF function synthesizer.
Keywords
- Dynamics
- Electron transport
- Magnetic structure
- Nanomagnet
- Nanoparticle
- Permalloy
- Vortex core
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics