Comparison of Sensitivity and Low-Frequency Noise Contributions in Giant-Magnetoresistive and Tunneling-Magnetoresistive Spin-Valve Sensors with a Vortex-State Free Layer

Author(s)
Herbert Weitensfelder, Hubert Brueckl, Armin Satz, Klemens Pruegl, Juergen Zimmer, Sebastian Luber, Wolfgang Raberg, Claas Abert, Florian Bruckner, Anton Bachleitner-Hofmann, Roman Windl, Dieter Suess
Abstract

Magnetoresistive spin-valve sensors based on the giant-magnetoresisitive (GMR) and tunneling-magnetoresisitive (TMR) effect with a flux-closed vortex-state free-layer design are compared by means of sensitivity and low-frequency noise. The vortex-state free layer allows high saturation fields up to 80 mT with negligible hysteresis, making it attractive for applications with a high dynamic range. The measured GMR devices comprise pink noise lower by a factor of 300 and better linearity in resistance but are less sensitive to external magnetic fields than TMR sensors. The results show comparable detectivity at low frequencies of about 2 mu T/root Hz for 1-mu m-diameter devices and 0.8 mu T/root Hz for 2-mu m-diameter devices at 1 Hz with ten active elements connected in series. The performance of the TMR minimum detectable field at frequencies in the white-noise limit is better by a factor of about 20 than that of the GMR devices.

Organisation(s)
Physics of Functional Materials
External organisation(s)
Donau-Universität Krems, Infineon Technologies Austria AG, Infineon Technologies AG
Journal
Physical Review Applied
Volume
10
No. of pages
7
ISSN
2331-7019
DOI
https://doi.org/10.1103/PhysRevApplied.10.054056
Publication date
11-2018
Peer reviewed
Yes
Austrian Fields of Science 2012
Materials physics
Keywords
Portal url
https://ucris.univie.ac.at/portal/en/publications/comparison-of-sensitivity-and-lowfrequency-noise-contributions-in-giantmagnetoresistive-and-tunnelingmagnetoresistive-spinvalve-sensors-with-a-vortexstate-free-layer(ec7034a8-b9ac-4007-80bb-10db5dc3f46a).html