THICKNESS DEPENDENCE OF MAGNETIZATION AND MAGNETOSTRICTION OF NiFe AND NiFeRh FILMS

Ounadjela, K.; Lefakis, H.; Speriosu, V. S.; Hwang, Chul Ju; Alexopoulos, P.

doi:10.1051/jphyscol:19888776

Cited by 22 publications

(15 citation statements)

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“…The saturation magnetization, Ms, can take values between 700 kA/m to 860 kA/m [19][20][21][22][23]. We found by VSM (vibrating sample magnetometer) measurements, on magnetic thin films with Permalloy (10 nm), that M S = 710 kA/m, which is in agreement with [22], which shows a decrease of the saturation magnetization for very thin films. For the exchange constant, A, values between 10 pJ/m [20] to 13 pJ/m are reported [19,21,23].…”

Section: Characterization Of the Gmr Sensorsupporting

confidence: 63%

“…For simulations, we assumed M s = 710 kA/m (saturation magnetization), A = 1.3 × 10 −11 J/m (exchange constant), and an anisotropy constant, K U = 804 J/m 3 along Ox axis. These are typical material parameters used in micromagnetic simulations [19][20][21][22][23]. The cell size is determined by the exchange length, l ex , which for Permalloy is 5 nm [20].…”

Section: Characterization Of the Gmr Sensormentioning

confidence: 99%

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High Sensitivity Differential Giant Magnetoresistance (GMR) Based Sensor for Non-Contacting DC/AC Current Measurement

Musuroi

Oproiu

Volmer

et al. 2020

Sensors

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This paper presents the design and implementation of a high sensitivity giant magnetoresistance (GMR) based current sensor with a broad range of applications. The novelty of our approach consists in using a double differential measurement system, based on commercial GMR sensors, with an adjustable biasing system used to linearize the field response of the system. The work aims to act as a fully-operational proof of concept application, with an emphasis on the mode of operation and methods to improve the sensitivity and linearity of the measurement system. The implemented system has a broad current measurement range from as low as 75 mA in DC and 150 mA in AC up to 4 A by using a single setup. The sensor system is also very low power, consuming only 6.4 mW. Due to the way the sensors are polarized and positioned above the U-shaped conductive band through which the current to be measured is flowing, the differential setup offers a sensitivity of about between 0.0272 to 0.0307 V/A (signal from sensors with no amplifications), a high immunity to external magnetic fields, low hysteresis effects of 40 mA, and a temperature drift of the offset of about −2.59×10−4 A/°C. The system provides a high flexibility in designing applications where local fields with very low amplitudes must be detected. This setup can be redesigned for a wide range of applications, thus allowing further specific optimizations, which would provide an even greater accuracy and a significantly extended operation range.

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Section: Characterization Of the Gmr Sensorsupporting

confidence: 63%

Section: Characterization Of the Gmr Sensormentioning

confidence: 99%

High Sensitivity Differential Giant Magnetoresistance (GMR) Based Sensor for Non-Contacting DC/AC Current Measurement

Musuroi

Oproiu

Volmer

et al. 2020

Sensors

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“…The M-dependent signal at 1 nm is below the experimental noise floor, indicating little or no ferromagnetic response for these very thin air-exposed films. We have verified that the loss of SH-MOKE, which is consistent with the observed suppression of ferromagnetism in thin NiFe-alloy films due to oxidation, 7 indeed correlates with the loss of ferromagnetism, using vibrating-sample magnetometry.…”

supporting

confidence: 81%

Observation of the transverse second-harmonic magneto-optic Kerr effect from Ni81Fe19 thin film structures

Crawford

Rogers

Silva

et al. 1996

Applied Physics Letters

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We report second-harmonic magneto-optic Kerr measurements on air-exposed, polycrystalline Ni 81 Fe 19 thin films, ranging in thickness from 1 nm to 2 m, on Al 2 O 3 coated Si ͑001͒. For samples thicker than 20 nm, in the transverse Kerr geometry, we observe a factor of 4 change in second-harmonic intensity upon magnetization reversal. For thin samples, we observe interference between second-harmonic fields from the various interfaces and deterioration of ferromagnetism in the 1 and 2 nm films. Modeling suggests that the Ni 81 Fe 19 /Al 2 O 3 interface has a larger second-order susceptibility than the air/Ni 81 Fe 19 surface.

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“…For the amorphous FeCoBSi layer one can assume thickness independent piezomagnetism down to a few nm as long as the stoichiometry is retained. 44 For the hexagonal wurtzite AlN structure the piezoelectric coefficient decreases below 500nm thickness 45,46 and dielectric losses which are critical for noise in sensors increase. Recently near bulk piezoelectric properties were achieved for 10nm AlN.…”

Section: Resultsmentioning

confidence: 99%

“…High piezoelectricity near bulk values has been achieved for 10nm thick AlN 42 and high piezomagnetism is expected in amorphous FeCoBSi down to a few nm thickness. 44 At smaller thicknesses microscopic models or models with local or graded properties may be required. The linear constitutive equations (1) -(4) describe the strain S in x-direction for each layer as a function of stress T and external fields.…”

Section: Theorymentioning

confidence: 99%

Resonant magnetoelectric response of composite cantilevers: Theory of short vs. open circuit operation and layer sequence effects

2015

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The magnetoelectric effect in layered composite cantilevers consisting of strain coupled layers of magnetostrictive (MS), piezoelectric (PE), and substrate materials is investigated for magnetic field excitation at bending resonance. Analytic theories are derived for the transverse magnetoelectric (ME) response in short and open circuit operation for three different layer sequences and results presented and discussed for the FeCoBSi-AlN-Si and the FeCoBSi-PZT-Si composite systems. Response optimized PE-MS layer thickness ratios are found to greatly change with operation mode shifting from near equal MS and PE layer thicknesses in the open circuit mode to near vanishing PE layer thicknesses in short circuit operation for all layer sequences. In addition the substrate layer thickness is found to differently affect the open and short circuit ME response producing shifts and reversal between ME response maxima depending on layer sequence. The observed rich ME response behavior for different layer thicknesses, sequences, operating modes, and PE materials can be explained by common neutral plane effects and different elastic compliance effects in short and open circuit operation.

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THICKNESS DEPENDENCE OF MAGNETIZATION AND MAGNETOSTRICTION OF NiFe AND NiFeRh FILMS

Cited by 22 publications

References 0 publications

High Sensitivity Differential Giant Magnetoresistance (GMR) Based Sensor for Non-Contacting DC/AC Current Measurement

High Sensitivity Differential Giant Magnetoresistance (GMR) Based Sensor for Non-Contacting DC/AC Current Measurement

Observation of the transverse second-harmonic magneto-optic Kerr effect from Ni81Fe19 thin film structures

Resonant magnetoelectric response of composite cantilevers: Theory of short vs. open circuit operation and layer sequence effects

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