Broadband Mag-Noise of Patterned Permalloy Thin Films

Author

Zhang, Hanqiao ; Li, Chaojiang ; Divan, Ralu ; Hoffmann, Axel ; Wang, Pingshan

Author_Institution

Holcombe Dept. of Electr. & Comput. Eng., Clemson Univ., Clemson, SC, USA

Volume

46

Issue

6

fYear

2010

fDate

6/1/2010 12:00:00 AM

Firstpage

2442

Lastpage

2445

Abstract

A Y-factor noise figure (NF) measurement method is developed to characterize high-frequency mag-noise of a 550 nm wide Permalloy strip array under different dc bias currents. The noise voltage density is obtained. The proposed lumped element transmission line model describes noise properties of the patterned Py array well. Measurement data show that rapid ferromagnetic resonance frequencies (FMR) shift induced by dc bias current is related to the excess magnetization fluctuation thermally created by the combined dc current Joule heating effects and orthogonal Oersted fields.

Keywords

Permalloy; ferromagnetic materials; ferromagnetic resonance; fluctuations; magnetic noise; magnetic thin films; magnetisation; metallic thin films; FMR; FeNi; broadband mag-noise; dc bias currents; dc current Joule heating effects; high-frequency mag-noise; lumped element transmission line model; magnetization fluctuation; noise figure measurement method; noise voltage density; orthogonal Oersted fields; patterned permalloy thin films; rapid ferromagnetic resonance frequencies shift; size 550 nm; wide Permalloy strip array; Current measurement; Frequency measurement; Magnetic field measurement; Magnetic resonance; Noise figure; Noise measurement; Resonant frequency; Transistors; Transmission line measurements; Voltage; Magnetic noise; Y-factor method; patterned permalloy thin films;

fLanguage

English

Journal_Title

Magnetics, IEEE Transactions on

Publisher

ieee

ISSN

0018-9464

Type

jour

DOI

10.1109/TMAG.2010.2040071

Filename

5467411