Effects of remanent magnetization on dynamic magnetomechanical and magnetic-sensing characteristics in bi-layer multiferroics

Influences of remanent magnetization on dynamic magnetomechanical mechanisms in a bi-layer asymmetric magnetoelectric (ME) laminate consisting of lead zirconate titanate and samarium iron alloy has been studied systematically, and the underlying hysteresis physics involved in dynamic magnetomechanical process as well as its magnetic-sensing characteristics was intensively characterized. To appreciate the distinct magnetostriction and ferromagnetism simultaneously in samarium iron alloy, key magnetomechanical parameters of dynamic piezomagnetic coefficient, Young's modulus and mechanical quality factors exhibit hysteresis behaviors under magnetic field application. Consequently, high sensitivity in proposed bi-payer laminate for field detection can be reached without the facilitation of additional bias field. Experimental results show that the ME output has an approximately linear correlation with the applied AC magnetic field, and the low-frequency and the detection limits at 1 kHz and 120 kHz can reach 2.3 × 10−6 T and 2.2 × 10−8 T, respectively. These unique features provide such an asymmetric ME composite great potentials for weak magnetic field detection without DC bias field.

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Bias Voltage Dependence of Sensing Characteristics in Tunneling Magnetoresistance Sensors

Sensors ◽

10.3390/s21072495 ◽

2021 ◽

Vol 21 (7) ◽

pp. 2495

Author(s):

Piotr Wiśniowski ◽

Maciej Nawrocki ◽

Jerzy Wrona ◽

Susana Cardoso ◽

Paulo. P. Freitas

Keyword(s):

Magnetic Field ◽

Bias Voltage ◽

Tunneling Current ◽

Tunneling Magnetoresistance ◽

Key Factors ◽

Field Detection ◽

Field Sensitivity ◽

Characteristic Features ◽

Sensing Characteristics ◽

The Magnetic Field

One of the characteristic features of tunneling magnetoresistance (TMR) sensors is a strong influence of bias voltage on tunneling current. Since fundamental sensing characteristics of the sensors are primarily determined by the tunneling current, the bias voltage should impact these characteristics. Previous research has indeed showed the influence of the bias voltage on the magnetic field detection and sensitivity. However, the effect has not been investigated for nonlinearity and hysteresis and the influence of bias voltage polarity has not yet been addressed. Therefore, this paper systematically investigates the dependence of field sensitivity, nonlinearity, hysteresis and magnetic field detection of CoFeB/MgO/CoFeB-based magnetoresistance sensors on bias voltage magnitude and polarity. The sensitivity and field detection of all sensors improved significantly with the bias, whereas the nonlinearity and hysteresis deteriorated. The sensitivity increased considerably (up to 32 times) and linearly with bias up to 0.6 V. The field detection also decreased substantially (up 3.9 times) with bias and exhibited the minimum values for the same magnitude under both polarities. Significant and linear increases with bias were also observed for nonlinearity (up to 26 times) and hysteresis (up to 33 times). Moreover, not only the voltage magnitude but also the polarity had a significant effect on the sensing characteristics. This significant, linear and simultaneous effect of improvement and deterioration of the sensing characteristics with bias indicates that both bias voltage magnitude and polarity are key factors in the control and modification of these characteristics.

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Non-Contact Harmonic Magnetic Field Detection for Parallel Steel Pipeline Localization and Defects Recognition

Measurement ◽

10.1016/j.measurement.2021.109534 ◽

2021 ◽

pp. 109534

Author(s):

Yizhen Zhao ◽

Xinhua Wang ◽

Tao Sun ◽

Yingchun Chen ◽

Lin Yang ◽

...

Keyword(s):

Magnetic Field ◽

Steel Pipeline ◽

Field Detection

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Triboelectric Nanogenerator using Multiferroic Materials: An Approach for Energy Harvesting and Self-Powered Magnetic Field Detection

Nano Energy ◽

10.1016/j.nanoen.2021.105964 ◽

2021 ◽

pp. 105964

Author(s):

Sugato Hajra ◽

Venkateswaran Vivekananthan ◽

Manisha Sahu ◽

Gaurav Khandelwal ◽

Nirmal Prashanth Maria Joseph Raj ◽

...

Keyword(s):

Magnetic Field ◽

Energy Harvesting ◽

Triboelectric Nanogenerator ◽

Multiferroic Materials ◽

Field Detection ◽

Self Powered

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Experimental investigations on finishing of a brass specimen by magneto-rheological honing technique

Journal of Micromanufacturing ◽

10.1177/25165984211015785 ◽

2021 ◽

pp. 251659842110157

Author(s):

Chinu Kumari ◽

Sanjay Kumar Chak

Keyword(s):

Magnetic Field ◽

Process Parameters ◽

Surface Finish ◽

Rotational Speed ◽

Field Application ◽

Surface Finishing ◽

Experimental Investigations ◽

Significant Parameter ◽

Magnetizing Current ◽

Magneto Rheological

Magneto-rheological abrasive honing (MRAH) is an unconventional surface finishing technique that relies on abrasives mixed with a unique finishing fluid, which changes its characteristics on magnetic field application. This process imparts nanometric-level surface finish with a significant amount of uniformity. Rotating motion of the workpiece and continuous reciprocation of the finishing fluid in the MRAH process are recognized as the major aspects for adopting this process in finishing non-magnetic materials. The finishing obtained through the MRAH process relies on the workpiece’s material properties and process parameters such as concentration of abrasives in finishing fluid, rotational speed of the workpiece, and magnetic field strength/magnetizing current. To study the efficacy of MRAH process, a parametric study was conducted by performing few experiments on a brass workpiece. Design of experiment approach was adopted to plan the experiments, and the effect of different values of magnetizing current, the concentration of abrasives, and rotational speed on the surface finish were analyzed through the application of analysis of variance (ANOVA). From ANOVA, the rotational speed was found as the most significant parameter with a contribution of 48.90% on % reduction in roughness value (%∇Ra). Around 57% of roughness reduction was obtained at the optimized value of process parameters.

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