Nonlinear AC response and noise of a giant magnetoresistive sensor

Citation
Jr. Petta et al., Nonlinear AC response and noise of a giant magnetoresistive sensor, IEEE MAGNET, 36(4), 2000, pp. 2057-2061
Citations number
12
Categorie Soggetti
Apllied Physucs/Condensed Matter/Materiales Science
Journal title
IEEE TRANSACTIONS ON MAGNETICS
ISSN journal
00189464 → ACNP
Volume
36
Issue
4
Year of publication
2000
Part
2
Pages
2057 - 2061
Database
ISI
SICI code
0018-9464(200007)36:4<2057:NARANO>2.0.ZU;2-U
Abstract
We compare bridge voltage response measurements to ac magnetic fields from a giant magnetoresistive sensor with noise measurements on the same sensor. The small-signal response (for applied ac magnetic fields between 0.1 mOe rms and 30 mOe) is much less than is the slope of a de voltage versus field curve, because of hysteretic effects. Noise statistics are used to estimat e the size and number of the sites at which domain realignments occur near the response peak, Similar estimates are made by using fine-structure on th e ac response curve. For ac fields of about 0.3 mOe rms, sharp spikes appea r in the field-dependent response, giving rise to Large harmonic distortion , varying in an irregular way with the ac amplitude. Domain sizes are estim ated for the regions, giving these nonlinear response spikes, and for the d omains, giving the magnetic noise, and a comparison based on a fluctuation- dissipation relation of the noise, and the response shows the importance of hysteresis.