Title :
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
fDate :
6/1/2010 12:00:00 AM
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;
Journal_Title :
Magnetics, IEEE Transactions on
DOI :
10.1109/TMAG.2010.2040071
