Radio frequency probe studies of magnetic nanostructures

Author

Spinu, L. ; Connor, C. J O ; Srikanth, H.

Author_Institution

Adv. Mater. Res. Inst., New Orleans Univ., LA, USA

Volume

37

Issue

4

fYear

2001

fDate

7/1/2001 12:00:00 AM

Firstpage

2188

Lastpage

2193

Abstract

Precise mapping of fundamental parameters like the anisotropy and switching fields is essential to understand the influence of the relaxation, interactions and other phenomena that govern the dynamic magnetic properties in magnetic nanostructures. Dynamic transverse susceptibility (χ_T) experiments provide a very sensitive and unique way to probe these features. Using sensitive resonant method based on a radio frequency (RF) tunnel-diode oscillator (TDO), we have, for the first time, mapped the complete variation of χ_T in the H-T plane in several nanoparticle systems covering the superparamagnetic and blocked regimes. The variation is described well using theoretical models taking into account the thermal relaxation and anisotropy field distribution

Keywords

magnetic anisotropy; magnetic particles; magnetic susceptibility; nanostructured materials; superparamagnetism; anisotropy; anisotropy field distribution; blocked regimes; dynamic magnetic properties; dynamic transverse susceptibility; interactions; magnetic nanostructures; radio frequency probe; relaxation; sensitive resonant method; superparamagnetic; switching fields; thermal relaxation; Anisotropic magnetoresistance; Magnetic anisotropy; Magnetic properties; Magnetic resonance; Magnetic switching; Nanostructures; Oscillators; Perpendicular magnetic anisotropy; Probes; Radio frequency;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/20.951120

Filename

951120