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.

scholarly journals Field- and Stress-Induced Magnetic Anisotropy in Nanocrystalline Fe-Based and Amorphous Co-Based Alloys

1999 ◽  
Vol 32 (1-4) ◽  
pp. 289-294
Author(s):  
V. A. Lukshina ◽  
N. V. Dmitrieva ◽  
A. P. Potapov
Keyword(s):  
Magnetic Field ◽  
Magnetic Properties ◽  
Amorphous Alloy ◽  
Magnetic Anisotropy ◽  
Thermomechanical Treatment ◽  
Nanocrystalline Alloy ◽  
Complex Effect ◽  
Induced Magnetic Anisotropy ◽  
The Magnetic Field

For nanocrystalline alloy Fe73.5Cu1Nb3Si13.5B9 thermomechanical treatment was carried out simultaneously with nanocrystallizing annealing (1) or after it (2). It was shown that a change in magnetic properties for the case 1 is essentially greater than for the case 2. Complex effect of thermomagnetic and thermomechanical treatments on magnetic properties was studied in the above-mentioned nanocrystalline alloy as well as in the amorphous alloy Fe5Co70.6Si15B9.4., During the annealings both field and stress were aligned with the long side of the specimens. It was shown that the magnetic field, AC or DC, decreases an effect of loading. Moreover, the magnetic field, AC or DC, applied after stress-annealing can destroy the magnetic anisotropy already induced under load.

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.

scholarly journals Effect of Co Substitution and Thermo-Magnetic Treatment on the Structure and Induced Magnetic Anisotropy of Fe84.5−xCoxNb5B8.5P2 Nanocrystalline Alloys

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3433
Author(s):  
Aleksandra Kolano-Burian ◽  
Przemyslaw Zackiewicz ◽  
Agnieszka Grabias ◽  
Anna Wojcik ◽  
Wojciech Maziarz ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Properties ◽  
Melt Spinning ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Transmission Electron ◽  
Induced Magnetic Anisotropy ◽  
Crystallization Effect ◽  
Magnetic Techniques

In the present work, we investigated in detail the thermal/crystallization behavior and magnetic properties of materials with Fe84.5-xCoxNb5B8.5P2 (x = 0, 5, 10, 15 and 20 at.%) composition. The amorphous ribbons were manufactured on a semi-industrial scale by the melt-spinning technique. The subsequent nanocrystallization processes were carried out under different conditions (with/without magnetic field). The comprehensive studies have been carried out using differential scanning calorimetry, X-ray diffractometry, transmission electron microscopy, hysteresis loop analyses, vibrating sample magnetometry and Mössbauer spectroscopy. Moreover, the frequency (up to 300 kHz) dependence of power losses and permeability at a magnetic induction up to 0.9 T was investigated. On the basis of some of the results obtained, we calculated the values of the activation energies and the induced magnetic anisotropies. The X-ray diffraction results confirm the surface crystallization effect previously observed for phosphorous-containing alloys. The in situ microscopic observations of crystallization describe this process in detail in accordance with the calorimetry results. Furthermore, the effect of Co content on the phase composition and the influence of annealing in an external magnetic field on magnetic properties, including the orientation of the magnetic spins, have been studied using various magnetic techniques. Finally, nanocrystalline Fe64.5Co20Nb5B8.5P2 cores were prepared after transverse thermo-magnetic heat treatment and installed in industrially available portable heating equipment.

scholarly journals Магнитный импеданс пленочных наноструктур для оценки полей рассеяния микрочастиц магнитных композитов

2022 ◽  
Vol 92 (2) ◽  
pp. 321
Author(s):  
Г.Ю. Мельников ◽  
В.Н. Лепаловский ◽  
Г.В. Курляндская
Keyword(s):  
Magnetic Field ◽  
Magnetic Properties ◽  
Magnetic Composite ◽  
Giant Magnetoimpedance ◽  
Giant Magnetoimpedance Effect ◽  
Magnetic Microparticles ◽  
Stray Magnetic Field ◽  
Weight Concentration ◽  
Maximum Value ◽  
Film Element

Longitudinal giant magnetoimpedance effect of [Fe21Ni79/Cu]5/Cu/[Fe21Ni79/Cu]5 film element was investigated depends on stray magnetic field of epoxy magnetic composite with 30 % weight concentration of iron oxide magnetic microparticles. Configuration of an experiment was a model of thrombus detection in a blood vessel. Stray magnetic field was varied by movement of a magnetic composite above the element perpendicular to the long side. Composite was either magnetized or not to the state of remanence. As the magnetic composite approaches the GMI element, MI ratio curves are smoothed and shifted along the field axis and maximum value of the MI ratio decreases. Magnetic properties of magnetic composite and film element were investigated as well.

scholarly journals Effects of Perpendicular Magnetic Field Annealing on the Structural and Magnetic Properties of [Co/Ni]2/PtMn Thin Films

2021 ◽  
Vol 7 (3) ◽  
pp. 38
Author(s):  
Roshni Yadav ◽  
Chun-Hsien Wu ◽  
I-Fen Huang ◽  
Xu Li ◽  
Te-Ho Wu ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Thin Films ◽  
Magnetic Properties ◽  
Photoelectron Spectroscopy ◽  
Perpendicular Magnetic Field ◽  
Face Centered Cubic ◽  
Lattice Image ◽  
X Ray ◽  
Field Annealing ◽  
Face Centered

In this study, [Co/Ni]2/PtMn thin films with different PtMn thicknesses (2.7 to 32.4 nm) were prepared on Si/SiO2 substrates. The post-deposition perpendicular magnetic field annealing (MFA) processes were carried out to modify the structures and magnetic properties. The MFA process also induced strong interlayer diffusion, rendering a less sharp interface between Co and Ni and PtMn layers. The transmission electron microscopy (TEM) lattice image analysis has shown that the films consisted of face-centered tetragonal (fct) PtMn (ordered by MFA), body-centered cubic (bcc) NiMn (due to intermixing), in addition to face-centered cubic (fcc) Co, Ni, and PtMn phases. The peak shift (2-theta from 39.9° to 40.3°) in X-ray diffraction spectra also confirmed the structural transition from fcc PtMn to fct PtMn after MFA, in agreement with those obtained by lattice images in TEM. The interdiffusion induced by MFA was also evidenced by the depth profile of X-ray photoelectron spectroscopy (XPS). Further, the magnetic properties measured by vibrating sample magnetometry (VSM) have shown an increased coercivity in MFA-treated samples. This is attributed to the presence of ordered fct PtMn, and NiMn phases exchange coupled to the ferromagnetic [Co/Ni]2 layers. The vertical shift (Mshift = −0.03 memu) of the hysteresis loops is ascribed to the pinned spins resulting from perpendicular MFA processes.

Effect of Thickness on Mechanically Tunable Magnetic Anisotropy of FeGa Thin Films Deposited on Flexible Substrates

2015 ◽  
Vol 815 ◽  
pp. 227-232 ◽  
Author(s):  
Ying Yu ◽  
Shu Hong Xie ◽  
Qing Feng Zhan
Keyword(s):  
Thin Films ◽  
Magnetic Properties ◽  
Magnetic Anisotropy ◽  
Effective Strain ◽  
Anisotropy Field ◽  
Saturation Field ◽  
Effective Anisotropy ◽  
Magnetostriction Constant ◽  
The Difference ◽  
Different Strains

A practical way to manipulate the magnetic anisotropy of magnetostrictive FeGa thin films grown on flexible polyethylene terephthalate (PET) substrates is introduced in this study. The effect of film thickness on magnetic properties and magnetostriction constant of polycrystalline FeGa thin films was investigated. The anisotropy field Hk of flexible FeGa films, i.e., the saturation field determined by fitting the hysteresis curves measured along the hard axis, was enhanced with increasing the tensile strain applied along the easy axis of the thin films, but this enhancement via strain became unconspicuous with increasing the thickness of FeGa films. In order to study the magnetic sensitivity of thin films responding to the external stress, we applied different strains on these films and measure the corresponding anisotropy field. Moreover, the effective magnetostriction constant of FeGa films was calculated from the changes of both anisotropy field and external strain based on the Villari effect. A Neel’s phenomenological model was developed to illustrate that the effective anisotropy field of FeGa thin films was contributed from both the constant volume term and the inverse thickness dependent surface term. Therefore, the magnetic properties for the volume and surface of FeGa thin films were different, which has been verified in this work by using vibrating sample magnetometer (VSM) and magneto-optic Kerr effect (MOKE) system. The anisotropy field contributed by the surface of FeGa film and obtained by MOKE is smaller than that contributed by the film volume and measured by VSM. We ascribed the difference in Hk to the relaxation of the effective strain applied on the films with increasing the thickness of films.

Magnetic Properties and Structure of the Alloy Fe63.5Ni10Cu1Nb3Si13.5B9 with Induced Magnetic Anisotropy

2021 ◽  
Vol 122 (6) ◽  
pp. 533-539
Author(s):  
V. A. Lukshina ◽  
N. V. Dmitrieva ◽  
E. G. Volkova ◽  
D. A. Shishkin
Keyword(s):  
Magnetic Properties ◽  
Magnetic Anisotropy ◽  
Induced Magnetic Anisotropy

scholarly journals X-Ray Study of Nanocrystalline Ribbons FeCuNbSiB Subjected to Thermomechanical and Thermomagnetic Treatments

2000 ◽  
Vol 34 (4) ◽  
pp. 227-232
Author(s):  
I. V. Gervasyeva ◽  
H. J. Bunge ◽  
K. Helming ◽  
V. A. Lukshina ◽  
I. V. Alexandrov
Keyword(s):  
Grain Size ◽  
Magnetic Anisotropy ◽  
Thermomagnetic Treatment ◽  
Internal Stresses ◽  
X Ray ◽  
Induced Magnetic Anisotropy

An attempt to discover the structure peculiarities giving rise to induced magnetic anisotropy in a finemet subjected to thermomechanical or thermomagnetic treatment has been undertaken. Grain size, internal stresses and texture in FeCuNbSiB ribbons were investigated. It was concluded that the induced magnetic anisotropy must have another reason e.g., directional ordering of Si atoms.

Sign in / Sign up

Export Citation Format

Share Document