Studies of magnetic properties and giant magnetoimpedance effect in ultrathin magnetically soft amorphous microwires

2008 ◽  
Vol 103 (7) ◽  
pp. 07E714 ◽  
Author(s):  
V. Zhukova ◽  
M. Ipatov ◽  
J. Gonzalez ◽  
J. M. Blanco ◽  
A. Zhukov
Keyword(s):  
Magnetic Properties ◽  
Giant Magnetoimpedance ◽  
Giant Magnetoimpedance Effect ◽  
Amorphous Microwires

Magnetic Properties and the Giant Magneto-Impedance in Joule-Heated Glass-Covered Co-Based Microwire

2009 ◽  
Vol 79-82 ◽  
pp. 1407-1410 ◽  
Author(s):  
B. Tian ◽  
L.H. Wang ◽  
L.Y. Zhou
Keyword(s):  
Magnetic Properties ◽  
Induced Anisotropy ◽  
Soft Magnetic ◽  
Applied Current ◽  
Giant Magnetoimpedance ◽  
Maximum Slope ◽  
Giant Magnetoimpedance Effect ◽  
Amorphous Microwires ◽  
Dc Current ◽  
Heated Glass

The influence of DC current annealing on magnetic properties and the frequency dependence in the range from 0.1 to 20 MHz of the giant magnetoimpedance effect (GMI) of glass-covered amorphous microwires were investigated. Under a certain annealing condition (10 min annealing with applied current Ia=110 mA), the maximum change of impedance was about 200% with a maximum slope sensitivity of 0.26%/Am-1 . Further treatment with increased current resulted in a decrease of the maximum MI ratio. Meanwhile, annealing can produce short-range order relaxation and consequently improves the sample's soft magnetic properties. We also found that the GMI ratio increased due to the enhanced induced anisotropy with increasing current under the same Joule energy.

scholarly journals Scattering of Microwaves by a Passive Array Antenna Based on Amorphous Ferromagnetic Microwires for Wireless Sensors with Biomedical Applications

Sensors ◽  
2019 ◽  
Vol 19 (14) ◽  
pp. 3060
Author(s):  
Alberto Moya ◽  
Diego Archilla ◽  
Elena Navarro ◽  
Antonio Hernando ◽  
Pilar Marín
Keyword(s):  
Biomedical Applications ◽  
High Sensitivity ◽  
Bias Field ◽  
Giant Magnetoimpedance ◽  
Scattering Parameter ◽  
Giant Magnetoimpedance Effect ◽  
Radiation Theory ◽  
Temperature Detector ◽  
Frequency Sweeps ◽  
Amorphous Microwires

Co-based amorphous microwires presenting the giant magnetoimpedance effect are proposed as sensing elements for high sensitivity biosensors. In this work we report an experimental method for contactless detection of stress, temperature, and liquid concentration with application in medical sensors using the giant magnetoimpedance effect on microwires in the GHz range. The method is based on the scattering of electromagnetic microwaves by FeCoSiB amorphous metallic microwires. A modulation of the scattering parameter is achieved by applying a magnetic bias field that tunes the magnetic permeability of the ferromagnetic microwires. We demonstrate that the OFF/ON switching of the bias activates or cancels the amorphous ferromagnetic microwires (AFMW) antenna behavior. We show the advantages of measuring the performing time dependent frequency sweeps. In this case, the AC-bias modulation of the scattering coefficient versus frequency may be clearly appreciated. Furthermore, this modulation is enhanced by using arrays of microwires with an increasing number of individual microwires according to the antenna radiation theory. Transmission spectra show significant changes in the range of 3 dB for a relatively weak magnetic field of 15 Oe. A demonstration of the possibilities of the method for biomedical applications is shown by means of wireless temperature detector from 0 to 100 °C.

Giant Magnetoimpedance Effect in a Co-Based Microwire for Quick-Response Magnetic Sensor Applications

Volume 3 ◽  
2004 ◽  
Author(s):  
Manh-Huong Phan ◽  
Hua-Xin Peng ◽  
Michael R. Wisnom ◽  
Seong-Cho Yu
Keyword(s):  
Giant Magnetoimpedance ◽  
New Approach ◽  
Giant Magnetoimpedance Effect ◽  
Sensor Applications ◽  
Sensing Applications ◽  
Stress Sensors ◽  
Field Sensitivity ◽  
Amorphous Microwires ◽  
Dc Current ◽  
Linear Field

Development of autobiased linear field sensors based on asymmetrical giant magnetoimpedance (AGMI) effect in Corich amorphous microwires upon the application of a biasing dc current is approached. Upon biasing dc currents, the highest field sensitivity of AGMI of 20%/Oe was found at a biasing dc current of 10 mA. The reduction of the AGMI under a biasing dc current of 25 mA and a frequency of 10 MHz has been observed. The result indicates that an optimum design of autobiased linear field sensors based on AGMI can be achieved by applying the biasing dc current of 10 mA and in the frequency range of 100 kHz–5 MHz. A stress-induced change in AGMI has also been found in these microwires and this offers a new approach to the development of stress sensors. All these features make the Co-rich amorphous microwire a multifunctional and smart material that can be used for different purposes of sensing applications.

Optimization of Magnetic Properties and Giant Magnetoimpedance Effect in Nanocrystalline Microwires

2014 ◽  
Vol 28 (3) ◽  
pp. 813-822 ◽  
Author(s):  
A. Zhukov ◽  
A. Talaat ◽  
M. Ipatov ◽  
J. J. del Val ◽  
L. Gonzalez-Legarreta ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Giant Magnetoimpedance ◽  
Giant Magnetoimpedance Effect

scholarly journals Optimization of magnetic properties and GMI effect of Thin Co-rich Microwires for GMI Microsensors

Sensors ◽  
2020 ◽  
Vol 20 (6) ◽  
pp. 1558 ◽  
Author(s):  
Lorena Gonzalez-Legarreta ◽  
Paula Corte-Leon ◽  
Valentina Zhukova ◽  
Mihail Ipatov ◽  
Juan Maria Blanco ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Magnetic Anisotropy ◽  
Hysteresis Loops ◽  
Transverse Magnetic ◽  
Wide Frequency Range ◽  
Soft Magnetic ◽  
Giant Magnetoimpedance ◽  
Giant Magnetoimpedance Effect ◽  
Annealing Temperatures ◽  
High Annealing

Magnetic microwires can present excellent soft magnetic properties and a giant magnetoimpedance effect. In this paper, we present our last results on the effect of postprocessing allowing optimization of the magnetoimpedance effect in Co-rich microwires suitable for magnetic microsensor applications. Giant magnetoimpedance effect improvement was achieved either by annealing or stress-annealing. Annealed Co-rich presents rectangular hysteresis loops. However, an improvement in magnetoimpedance ratio is observed at fairly high annealing temperatures over a wide frequency range. Application of stress during annealing at moderate values of annealing temperatures and stress allows for a remarkable decrease in coercivity and increase in squareness ratio and further giant magnetoimpedance effect improvement. Stress-annealing, carried out at sufficiently high temperatures and/or stress allowed induction of transverse magnetic anisotropy, as well as magnetoimpedance effect improvement. Enhanced magnetoimpedance ratio values for annealed and stress-annealed samples and frequency dependence of the magnetoimpedance are discussed in terms of the radial distribution of the magnetic anisotropy. Accordingly, we demonstrated that the giant magnetoimpedance effect of Co-rich microwires can be tailored by controlling the magnetic anisotropy of Co-rich microwires, using appropriate thermal treatment.

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