Broadband Magnetic Response of Periodic Arrays of FeNi Dots

Author

Sierra, Juan Francisco ; Awad, Ahmad A. ; Kakazei, Gleb N. ; Palomares, Francisco Javier ; Aliev, Farkhad G.

Author_Institution

Dept. de Fis. de la Materia Condensada. C III, Univ. Autonoma de Madrid, Madrid

Volume

44

Issue

11

fYear

2008

Firstpage

3063

Lastpage

3066

Abstract

We present a study of magnetization dynamics at room temperature in periodic arrays of 50 nm thick FeNi (Py) circular magnetic dots of 500 nm radius and different center to center distance (1200 and 2500 nm), by using a broadband magnetometer based on vector network analyzer which works between 300 kHz and 8.5 GHz. We also present a comparison between the dynamic response, ferromagnetic resonance (FMR) and its linewidth, with static magnetic characteristics such as magnetization curves. The FMR peak appears just above the nucleation field and is perfectly described by Kittel formula taking into account the demagnetizing factor of an individual magnetic dot. In addition to FMR we observed a spin wave resonance below the uniform mode, which could be attributed to spin waves in confined systems. The FMR linewidth shows a significant broadening close to the field region corresponding to nucleation of magnetic vortex.

Keywords

demagnetisation; ferromagnetic materials; ferromagnetic resonance; high-frequency effects; iron alloys; magnetisation; nanomagnetics; nanostructured materials; nickel; nickel alloys; nucleation; FMR linewidth; FeNi; Kittel formula; broadband magnetic response; broadband magnetometer; demagnetizing factor; ferromagnetic resonance; frequency 300 kHz to 8.5 GHz; magnetic vortex; magnetization dynamics; nucleation; periodic circular magnetic dot arrays; size 50 nm; size 500 nm; spin wave resonance; vector network analyzer; Magnetic devices; magnetic resonance; nanotechnology;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/TMAG.2008.2002527

Filename

4717402