The Influence of Dimensional Parameters on the Characteristics of Magnetic Flux Concentrators Used in Tunneling Magnetoresistance Devices

Measuring weak magnetic fields proposes significant challenges to the sensing capabilities of magnetic field sensors. The magnetic field detection capacity of tunnel magnetoresistance (TMR) sensors is often insufficient for such applications, necessitating targeted optimization strategies to improve...

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Main Authors: Ran Bi, Huiquan Zhang, Shi Pan, Xinting Liu, Ruiying Chen, Shilin Wu, Jun Hu
Format: Article
Language:English
Published: MDPI AG 2025-07-01
Series:Sensors
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Online Access:https://www.mdpi.com/1424-8220/25/15/4739
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author Ran Bi
Huiquan Zhang
Shi Pan
Xinting Liu
Ruiying Chen
Shilin Wu
Jun Hu
author_facet Ran Bi
Huiquan Zhang
Shi Pan
Xinting Liu
Ruiying Chen
Shilin Wu
Jun Hu
author_sort Ran Bi
collection DOAJ
description Measuring weak magnetic fields proposes significant challenges to the sensing capabilities of magnetic field sensors. The magnetic field detection capacity of tunnel magnetoresistance (TMR) sensors is often insufficient for such applications, necessitating targeted optimization strategies to improve their performance in weak-field measurements. Utilizing magnetic flux concentrators (MFCs) offers an effective approach to enhance TMR sensitivity. In this study, the finite element method was employed to analyze the effects of different MFC geometric structures on the uniformity of the magnetic field in the air gap and the magnetic circuit gain (MCG). It was determined that the MCG of the MFC is not directly related to the absolute values of its parameters but rather to their ratios. Simulation analyses evaluated the impact of these parameter ratios on both the MCG and its spatial distribution uniformity, leading to the formulation of MFC design optimization principles. Building on these simulation-derived principles, several MFCs were fabricated using the 1J85 material, and an experimental platform was established to validate the simulation findings. The fabricated MFCs achieved an MCG of 7.325 times. Based on the previously developed TMR devices, a detection sensitivity of 2.46 nT/<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msqrt><mi>Hz</mi></msqrt></semantics></math></inline-formula> @1Hz was obtained. By optimizing parameter configurations, this work provides theoretical guidance for further enhancing the performance of TMR sensors in magnetic field measurements.
format Article
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issn 1424-8220
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spelling doaj-art-73c0d392861346848a59de0e4b04ce852025-08-20T03:02:51ZengMDPI AGSensors1424-82202025-07-012515473910.3390/s25154739The Influence of Dimensional Parameters on the Characteristics of Magnetic Flux Concentrators Used in Tunneling Magnetoresistance DevicesRan Bi0Huiquan Zhang1Shi Pan2Xinting Liu3Ruiying Chen4Shilin Wu5Jun Hu6Department of Electrical Engineering, Tsinghua University, Beijing 100084, ChinaDepartment of Electrical Engineering, Tsinghua University, Beijing 100084, ChinaDepartment of Electrical Engineering, Tsinghua University, Beijing 100084, ChinaDepartment of Electrical Engineering, Tsinghua University, Beijing 100084, ChinaDepartment of Electrical Engineering, Tsinghua University, Beijing 100084, ChinaDepartment of Electrical Engineering, Tsinghua University, Beijing 100084, ChinaDepartment of Electrical Engineering, Tsinghua University, Beijing 100084, ChinaMeasuring weak magnetic fields proposes significant challenges to the sensing capabilities of magnetic field sensors. The magnetic field detection capacity of tunnel magnetoresistance (TMR) sensors is often insufficient for such applications, necessitating targeted optimization strategies to improve their performance in weak-field measurements. Utilizing magnetic flux concentrators (MFCs) offers an effective approach to enhance TMR sensitivity. In this study, the finite element method was employed to analyze the effects of different MFC geometric structures on the uniformity of the magnetic field in the air gap and the magnetic circuit gain (MCG). It was determined that the MCG of the MFC is not directly related to the absolute values of its parameters but rather to their ratios. Simulation analyses evaluated the impact of these parameter ratios on both the MCG and its spatial distribution uniformity, leading to the formulation of MFC design optimization principles. Building on these simulation-derived principles, several MFCs were fabricated using the 1J85 material, and an experimental platform was established to validate the simulation findings. The fabricated MFCs achieved an MCG of 7.325 times. Based on the previously developed TMR devices, a detection sensitivity of 2.46 nT/<inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><msqrt><mi>Hz</mi></msqrt></semantics></math></inline-formula> @1Hz was obtained. By optimizing parameter configurations, this work provides theoretical guidance for further enhancing the performance of TMR sensors in magnetic field measurements.https://www.mdpi.com/1424-8220/25/15/4739magnetic sensorsmagnetic circuitmagnetic flux concentratorfinite element simulationtunneling magnetoresistance
spellingShingle Ran Bi
Huiquan Zhang
Shi Pan
Xinting Liu
Ruiying Chen
Shilin Wu
Jun Hu
The Influence of Dimensional Parameters on the Characteristics of Magnetic Flux Concentrators Used in Tunneling Magnetoresistance Devices
Sensors
magnetic sensors
magnetic circuit
magnetic flux concentrator
finite element simulation
tunneling magnetoresistance
title The Influence of Dimensional Parameters on the Characteristics of Magnetic Flux Concentrators Used in Tunneling Magnetoresistance Devices
title_full The Influence of Dimensional Parameters on the Characteristics of Magnetic Flux Concentrators Used in Tunneling Magnetoresistance Devices
title_fullStr The Influence of Dimensional Parameters on the Characteristics of Magnetic Flux Concentrators Used in Tunneling Magnetoresistance Devices
title_full_unstemmed The Influence of Dimensional Parameters on the Characteristics of Magnetic Flux Concentrators Used in Tunneling Magnetoresistance Devices
title_short The Influence of Dimensional Parameters on the Characteristics of Magnetic Flux Concentrators Used in Tunneling Magnetoresistance Devices
title_sort influence of dimensional parameters on the characteristics of magnetic flux concentrators used in tunneling magnetoresistance devices
topic magnetic sensors
magnetic circuit
magnetic flux concentrator
finite element simulation
tunneling magnetoresistance
url https://www.mdpi.com/1424-8220/25/15/4739
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