Development of a very high sensitivity magnetic field sensor based on planar Hall effect

Roy, A and Sampathkumar, P and Anil Kumar, PS (2020) Development of a very high sensitivity magnetic field sensor based on planar Hall effect. In: Measurement: Journal of the International Measurement Confederation, 156 .

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Abstract

While planar Hall effect based magnetic field detection is a well-studied area, the sensing capabilities of �Hall cross� sensors had not improved significantly for more than a decade. Here we report a major improvement in the sensing characteristics of �cross� geometry by using pulsed laser ablation grown Permalloy as sensing material. Our sensor has two modes of operation. In the linear regime, it has a field sensitivity of 650 Ω/T with an estimated detection threshold of 5nT in open-loop condition. In switching applications, it shows a 400 output voltage swing in a range of ±0.3 mT, a value comparable with modern TMR sensors at room temperature. These values, which are the highest reported for the �cross� geometry, make it applicable in a wide range of scenarios like geomagnetic field and magnetic anomaly detection. The small size of the sensing area also makes it a desirable choice for magnetic microbead based biomolecule detection.

Item Type:	Journal Article
Publication:	Measurement: Journal of the International Measurement Confederation
Publisher:	Elsevier
Additional Information:	The copyright of this article belongs to Elsevier
Keywords:	Anomaly detection; Geomagnetism; Hall effect; Iron alloys; Laser ablation; Magnetic sensors; Magnetometers; Nickel alloys; Permalloy, Geomagnetic fields; Low magnetic fields; Magnetic anomalies; Magnetic anomaly detection; Magnetic field sensors; Planar Hall effect; Sensing characteristics; Switching applications, Hall effect transducers
Department/Centre:	Division of Physical & Mathematical Sciences > Physics
Date Deposited:	09 Mar 2020 09:47
Last Modified:	09 Mar 2020 09:47
URI:	http://eprints.iisc.ac.in/id/eprint/64766

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