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.

Giant magnetoimpedance in CoP electrodeposited microtubes

2000 ◽  
Vol 15 (3) ◽  
pp. 751-755 ◽  
Author(s):  
J. P. Sinnecker ◽  
J. M. García ◽  
A. Asenjo ◽  
M. Vázquez ◽  
A. García-Arribas
Keyword(s):  
Magnetic Anisotropy ◽  
Layer Thickness ◽  
Magnetic Force Microscopy ◽  
Magnetic Force ◽  
Hysteresis Loops ◽  
Giant Magnetoimpedance ◽  
Microscopy Imaging ◽  
Giant Magnetoimpedance Effect ◽  
Force Microscopy ◽  
Radial Anisotropy

Co90P10 amorphous microtubes with thickness ranging from 2 to 19 μm were electrodeposited onto Cu wire substrates. Samples exhibit radial magnetic anisotropy as deduced from hysteresis loops and magnetic force microscopy imaging. These microtubes show quite noticeable giant magnetoimpedance effect (GMI) with amplitude depending on layer thickness and frequency. The hysteresis in the GMI curves is small, which can be ascribed to the radial anisotropy. Such small hysteresis is of importance for technological applications.

scholarly journals Stress-Induced Magnetic Anisotropy Enabling Engineering of Magnetic Softness and GMI Effect of Amorphous Microwires

2020 ◽  
Vol 10 (3) ◽  
pp. 981 ◽  
Author(s):  
Paula Corte-León ◽  
Ahmed Talaat ◽  
Valentina Zhukova ◽  
Mihail Ipatov ◽  
Juan María Blanco ◽  
...  
Keyword(s):  
Magnetic Anisotropy ◽  
Hysteresis Loops ◽  
Transverse Magnetic ◽  
Wide Frequency Range ◽  
Frequency Range ◽  
Gmi Effect ◽  
Annealing Conditions ◽  
Induced Magnetic Anisotropy ◽  
Magnetic Softness ◽  
Amorphous Microwires

Stress-annealing enabled a considerable improvement in the GMI effect in both Fe- and Co-rich glass-coated microwires. Additionally, a remarkable magnetic softening can be achieved in stress-annealed Fe-rich microwires. Observed stress-annealing induced magnetic anisotropy is affected by annealing conditions (temperatures and stresses applied during annealing). The highest GMI ratio up to 310% was obtained in stress-annealed Co-rich microwires, although they presented rectangular hysteresis loops. A remarkable magnetic softness and improved GMI ratio over a wide frequency range were obtained in stress-annealed Fe-rich microwires. Irregular magnetic field dependence observed for some stress-annealing conditions is attributed to the contribution of both the inner axially magnetized core and outer shell, with transverse magnetic anisotropy.

Microstructures and Magnetic Properties of Sputtered Expitaxial Co3Pt/Pt Multilayer Films

2008 ◽  
Vol 47-50 ◽  
pp. 583-587
Author(s):  
S.C. Chen ◽  
Po Cheng Kuo ◽  
Chih Long Shen ◽  
Y.H. Fang ◽  
S.L. Hsu
Keyword(s):  
Magnetic Properties ◽  
Magnetic Anisotropy ◽  
Epitaxial Growth ◽  
Annealing Temperature ◽  
Perpendicular Magnetic Anisotropy ◽  
Multilayer Films ◽  
Soft Magnetic Properties ◽  
Soft Magnetic ◽  
Annealing Temperatures

Co3Pt films were deposited on Pt underlayers with various thicknesses by conventional sputtering in order to investigate the effect of Pt underlayers and annealing temperatures on their microstructure and the magnetic properties. From XRD and HRTEM analysises, as annealing at 300°C, a well epitaxial growth of Co3Pt (002) on Pt (111) underlayer that leads the film to present perpendicular magnetic anisotropy. However, Pt atoms in the Pt underlayer will diffuse seriously into Co3Pt layer as the annealing temperature is increased to 375°C that changes the compositions to approach equiatomic CoPt, and showing in-plane magnetic anisotropy with soft magnetic properties.

scholarly journals Influence of Various Heat Treatments on Giant Magnetoimpedance Effect in Nanocrystalline FeSiBNbCu Ribbons

1999 ◽  
Vol 32 (1-4) ◽  
pp. 269-279 ◽  
Author(s):  
G. V. Kurlyandskaya ◽  
M. Vázquez ◽  
E. H.C.P. Sinnecker ◽  
A. P. Zhukov ◽  
J. P. Sinnecker ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Properties ◽  
Magnetic Anisotropy ◽  
Zero Field ◽  
Fixed Frequency ◽  
Giant Magnetoimpedance ◽  
Giant Magnetoimpedance Effect ◽  
X Ray ◽  
Induced Magnetic Anisotropy ◽  
Magnetostriction Constant

In this paper we present studies on the frequency dependence of the magneto-impedance in the range of 0.1–2 MHz for Fe73.5Si13.5B9Nb3Cu1 and Fe73.5Si16.5B6Nb3Cu1 nanocrystalline ribbons, which differ in the sign of the magnetostriction constant. As cast samples were annealed in Ar atmosphere at 560℃, with and without an DC and AC magnetic field. At a fixed frequency, an improvement in the field annealed 13.5% Si samples, when compared with the zero field annealed ones, can be observed. On the 16.5% Si field annealed samples only a reduction of magneto-impedance ratio could be observed, when compared to the non-field annealed ones. Analysis of the magnetic properties and X-ray data shows that the observed changes in magneto-impedance effect are consequence of the induced magnetic anisotropy.

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 Engineering of giant magnetoimpedance effect of amorphous and nanocrystalline microwires

2016 ◽  
Vol 5 (3) ◽  
pp. 63
Author(s):  
V. Zhukova ◽  
A. Talaat ◽  
M. Ipatov ◽  
A. Granovsky ◽  
A. Zhukov
Keyword(s):  
Magnetic Properties ◽  
Soft Magnetic Properties ◽  
Soft Magnetic ◽  
Giant Magnetoimpedance ◽  
Magnetoelastic Anisotropy ◽  
Giant Magnetoimpedance Effect ◽  
Factors Affecting ◽  
Gmi Effect ◽  
Magnetic Softness

We present our studies of the factors affecting soft magnetic properties and giant magnetoimpedance effect in thin amorphous and nanocrystalline microwires. We showed that the magnetoelastic anisotropy is one of the most important parameters that determine magnetic softness and GMI effect of glass-coated microwires  and annealing can be very effective for manipulation the magnetic properties of amorphous ferromagnetic glass-coated microwires. Considerable magnetic softening and increasing of the GMI effect is observed in Fe-rich nanocrystalline FINEMET-type glass-coated microwires after the nanocrystallization.

scholarly journals Optimization of Magnetic Properties of Magnetic Microwires by Post-Processing

Processes ◽  
2020 ◽  
Vol 8 (8) ◽  
pp. 1006
Author(s):  
Valentina Zhukova ◽  
Paula Corte-Leon ◽  
Lorena González-Legarreta ◽  
Ahmed Talaat ◽  
Juan Maria Blanco ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Chemical Composition ◽  
Hysteresis Loops ◽  
Structural Features ◽  
Post Processing ◽  
Soft Magnetic ◽  
Magnetic Microwires ◽  
Prepared State ◽  
Induced Magnetic Anisotropy ◽  
Selection Of

The influence of post-processing conditions on the magnetic properties of amorphous and nanocrystalline microwires has been thoroughly analyzed, paying attention to the influence of magnetoelastic, induced and magnetocrystalline anisotropies on the hysteresis loops of Fe-, Ni-, and Co-rich microwires. We showed that magnetic properties of glass-coated microwires can be tuned by the selection of appropriate chemical composition and geometry in as-prepared state or further considerably modified by appropriate post-processing, which consists of either annealing or glass-coated removal. Furthermore, stress-annealing or Joule heating can further effectively modify the magnetic properties of amorphous magnetic microwires owing to induced magnetic anisotropy. Devitrification of microwires can be useful for either magnetic softening or magnetic hardening of the microwires. Depending on the chemical composition of the metallic nucleus and on structural features (grain size, precipitating phases), nanocrystalline microwires can exhibit either soft magnetic properties or semi-hard magnetic properties. We demonstrated that the microwires with coercivities from 1 A/m to 40 kA/m can be prepared.

Effects of Heat Treatment Conditions on Magnetic Properties and Structural Features of Nanocrystalline Fe79Zr10N11 Films

2009 ◽  
Vol 152-153 ◽  
pp. 70-74 ◽  
Author(s):  
E.N. Sheftel ◽  
Rauf S. Iskhakov ◽  
S.V. Komogortsev ◽  
P.K. Sidorenko ◽  
Nikolai S. Perov
Keyword(s):  
Heat Treatment ◽  
Magnetic Properties ◽  
Magnetic Anisotropy ◽  
Structural Features ◽  
Soft Magnetic ◽  
Exchange Correlation ◽  
Calculation Technique ◽  
Treatment Conditions ◽  
Random Magnetic Anisotropy ◽  
Anisotropy Model

Data on the random magnetic anisotropy and exchange correlation length in soft magnetic nanocrystalline Fe79Zr10N11 films were obtained using a calculation technique in frame of the random magnetic anisotropy model. The calculations are performed using approach magnetization to saturation curves. The local magnetic anisotropy fields (Ha), and magnetic anisotropy correlation radii (Rс) reduced to =(A/K)1/2 were determined for the films annealed at 475 and 6000 C for 0.5, 1, 2, and 3 h. The correlation Hc ~(Rc/)3 for the all annealed films was found.

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