Planar Hall Effect Magnetometer With 5 pT Resolution

Nhalil, Hariharan; Givon, Tzahi; Das, Proloy T.; Hasidim, Nir; Mor, Vladislav; Schultz, Moty; Amrusi, Shai; Klein, Lior; Grosz, Asaf

doi:10.1109/lsens.2019.2947681

Cited by 22 publications

(15 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Besides, ±100 nV noise level of PHE sensor signal provides a 1.6 µ T magnetic field resolution for 1 mA sensor current. This resolution can be enhanced by increasing the sensor current ( i x ) and reducing the sensor's noise levels [32]. The data shows that the sensor states are quite stable and repeatable under positive and negative polarities of the magnetic field.…”

Section: Magnetic Properties ( Hmentioning

confidence: 98%

Tuning the magnetic field sensitivity of planar Hall effect sensors by using a Cr spacer layer in a NiFe/Cr/IrMn trilayer structure

Pişkin¹,

Akdoğan²

2020

Turk J Phys

View full text Add to dashboard Cite

Planar Hall effect (PHE)-based magnetic field sensors have recently received considerable attention due to their fascinating properties. For the NiFe/spacer/IrMn trilayer PHE sensor structures, tuning the exchange bias via a spacer layer is very crucial due to its direct effects on the sensor's magnetic field sensitivity. Here the effect of Cr spacer layer thickness on PHE sensitivity and exchange bias is investigated in NiFe (10 nm)/Cr (t Cr ) /IrMn (20 nm) trilayer structures where the t Cr varied between 0.0 nm and 1 nm with a step of 0.1 nm. As the t Cr increased, we observed a fast decrease in exchange bias field. When the thickness of Cr spacer layer increased up to 0.7 nm, a maximum sensitivity of 4.4 µ V/(Oe • mA) was obtained. Besides, sensor voltage exhibited ±100 nV noise level. With this noise level, a 1.6 µ T magnetic field resolution was achieved.

show abstract

Section: Magnetic Properties ( Hmentioning

confidence: 98%

Tuning the magnetic field sensitivity of planar Hall effect sensors by using a Cr spacer layer in a NiFe/Cr/IrMn trilayer structure

Pişkin¹,

Akdoğan²

2020

Turk J Phys

View full text Add to dashboard Cite

show abstract

“…The thin film needs magnetic anisotropy to achieve this characteristic, whereas the easy axis is parallel to the current direction. Different techniques to achieve the magnetic anisotropy were reviewed by Mor et al [ 17 ], including field-induced magnetic anisotropy [ 24 , 25 , 26 , 27 ], spin valve structure [ 28 , 29 , 30 ], bridge structure [ 24 , 25 , 26 , 31 , 32 , 33 , 34 ], and shape-induced magnetic anisotropy [ 22 , 35 , 36 , 37 ]. The shape-induced approach has the unique advantage of simplified fabrication with a single ferromagnetic layer structure.…”

Section: Introductionmentioning

confidence: 99%

Design and Optimisation of Elliptical-Shaped Planar Hall Sensor for Biomedical Applications

et al. 2022

View full text Add to dashboard Cite

The magnetic beads detection-based immunoassay, also called magneto-immunoassay, has potential applications in point-of-care testing (POCT) due to its unique advantage of minimal background interference from the biological sample and associated reagents. While magnetic field detection technologies are well established for numerous applications in the military, as well as in geology, archaeology, mining, spacecraft, and mobile phones, adaptation into magneto-immunoassay is yet to be explored. The magnetic field biosensors under development tend to be multilayered and require an expensive fabrication process. A low-cost and affordable biosensing platform is required for an effective point-of-care diagnosis in a resource-limited environment. Therefore, we evaluated a single-layered magnetic biosensor in this study to overcome this limitation. The shape-induced magnetic anisotropy-based planar hall effect sensor was recently developed to detect a low-level magnetic field, but was not explored for medical application. In this study, the elliptical-shaped planar hall effect (EPHE) sensor was designed, fabricated, characterized, and optimized for the magneto-immunoassay, specifically. Nine sensor variants were designed and fabricated. A customized measurement setup incorporating a lock-in amplifier was used to quantify 4.5 µm magnetic beads in a droplet. The result indicated that the single-domain behaviour of the magnetic film and larger sensing area with a thinner magnetic film had the highest sensitivity. The developed sensor was tested with a range of magnetic bead concentrations, demonstrating a limit of detection of 200 beads/μL. The sensor performance encourages employing magneto-immunoassay towards developing a low-cost POCT device in the future.

show abstract

“…Extremely-low magnetic field sensing in the low-frequency range is an important task for a wide range of application areas such as magnetic random access memory (MRAM) [ 1 ], neuromorphic computing [ 2 ], magnetic communication [ 3 , 4 ], noninvasive biomedical diagnosis [ 5 , 6 , 7 , 8 ], nondestructive materials evaluation [ 9 ], human–machine interaction [ 10 , 11 ], robotics [ 12 ], and automotive or consumer-based industrials [ 13 ]. Most of these applications demand miniaturization, low-cost fabrication, high thermal stability, flexibility in usage, and robustness in a harsh environment with a very high sensor resolution [ 14 , 15 , 16 , 17 ]. In this perspective, many researchers have been involved in the development of an ultra-sensitive magnetic sensor over the past ten years, and it has been found that magnetoresistive (MR) sensor is always one of the best choices due to its high scalability and inherent capability to install ROIC (readout integration circuit) and also due to its excellent integration compatibility with CMOS (complementary metal-oxide-semiconductor) MEMS (micro-electro-mechanical systems) devices [ 18 , 19 , 20 , 21 ].…”

Section: Introductionmentioning

confidence: 99%

“…Thus, there are still many open questions regarding 1/f noise characteristics, which limit the high signal-to-noise ratio required for low-frequency applications below 10 Hz. Different strategies have been demonstrated to reduce the low-frequency noise in MR sensors [ 24 , 25 , 26 , 27 ] by integrating magnetic flux concentrators [ 14 , 15 , 20 ], implementing hybrid magnetic-MEMS devices [ 28 ], magnetic tunnel junction stacks [ 29 ], or large sensor arrays [ 30 , 31 ].…”

Section: Introductionmentioning

confidence: 99%

Operational Parameters for Sub-Nano Tesla Field Resolution of PHMR Sensors in Harsh Environments

Jeon

Das

Kim

et al. 2021

Sensors

Self Cite

View full text Add to dashboard Cite

The resolution of planar-Hall magnetoresistive (PHMR) sensors was investigated in the frequency range from 0.5 Hz to 200 Hz in terms of its sensitivity, average noise level, and detectivity. Analysis of the sensor sensitivity and voltage noise response was performed by varying operational parameters such as sensor geometrical architectures, sensor configurations, sensing currents, and temperature. All the measurements of PHMR sensors were carried out under both constant current (CC) and constant voltage (CV) modes. In the present study, Barkhausen noise was revealed in 1/f noise component and found less significant in the PHMR sensor configuration. Under measured noise spectral density at optimized conditions, the best magnetic field detectivity was achieved better than 550 pT/√Hz at 100 Hz and close to 1.1 nT/√Hz at 10 Hz for a tri-layer multi-ring PHMR sensor in an unshielded environment. Furthermore, the promising feasibility and possible routes for further improvement of the sensor resolution are discussed.

show abstract

Planar Hall Effect Magnetometer With 5 pT Resolution

Cited by 22 publications

References 29 publications

Tuning the magnetic field sensitivity of planar Hall effect sensors by using a Cr spacer layer in a NiFe/Cr/IrMn trilayer structure

Tuning the magnetic field sensitivity of planar Hall effect sensors by using a Cr spacer layer in a NiFe/Cr/IrMn trilayer structure

Design and Optimisation of Elliptical-Shaped Planar Hall Sensor for Biomedical Applications

Operational Parameters for Sub-Nano Tesla Field Resolution of PHMR Sensors in Harsh Environments

Contact Info

Product

Resources

About