scholarly journals Влияние отжига в постоянном магнитном поле на магнитные свойства сплавов железо--галлий

2020 ◽  
Vol 62 (10) ◽  
pp. 1578
Author(s):  
В.А. Лукшина ◽  
Д.А. Шишкин ◽  
А.Р. Кузнецов ◽  
H.В. Ершов ◽  
Ю.Н. Горностырев
Keyword(s):  
Magnetic Field ◽  
Magnetic Properties ◽  
Coercive Force ◽  
Magnetic Hysteresis ◽  
Hysteresis Loops ◽  
Residual Induction ◽  
Dc Magnetic Field ◽  
Saturation Induction ◽  
Field Annealing ◽  
Gallium Content

The concentration dependence of the magnetic properties of iron alloys with 3 – 25 at.% gallium has been studied. It is shown that with increasing gallium content, saturation induction decreases monotonically, but coercive force shows a stepped increase with a jump from 85 to 135 A/m between 12 and 15 at.% Ga. The effect of annealing in a dc magnetic field (magnetic field annealing (MFA)) on the behavior of residual induction and coercive force in samples containing from 3 to 18 at.% of gallium was investigated. After the MFA, in the alloy a magnetic anisotropy is induced: magnetic hysteresis loops become narrower, the residual induction increases and the coercive force decreases. The MFA efficiency reaches a maximum when the gallium content is at 15 – 18 at.%. The features of the structural state in iron-gallium alloys and their role in the formation of the magnetic properties during annealing in the dc magnetic field are discussed.

scholarly journals A laboratory magnetometer for express measurements of magnetic hysteresis loops

2021 ◽  
Vol 26 (2) ◽  
pp. 32-36
Author(s):  
K. Sova ◽  
◽  
A. Vakula ◽  
S. Polevoy ◽  
S. Tarapov ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Properties ◽  
External Magnetic Field ◽  
Magnetic Materials ◽  
Magnetic Hysteresis ◽  
Hysteresis Loops ◽  
Storage Conditions ◽  
Field Method ◽  
Magnetic Nanomaterials ◽  
Magnetic Hysteresis Loops

Subject and Purpose. The development of technologies for synthesis of nanoscale magnetic materials requires new techniques for measuring magnetic properties of nanoscale magnetic materials in such a way as to provide express post-synthesis measurements of magnetic properties and exclude, in doing so, any mechanical displacements of measured specimens. Despite the fact that numerous techniques exist for studying magnetic properties of materials, the development of such magnetic nanomaterials as magnetic nanoparticles faces the need in novel measuring approaches based on standard procedures. Novel express techniques are called to gain information about how magnetic properties of magnetic materials vary over time and respond to such factors as temperature, storage conditions, stabilizing agents, exposure to an external magnetic field. Method and Methodology. In this work, magnetic hysteresis loops are registered using a newly developed technique based on the method of small disturbances (by an external magnetic field) and combining standard constructions of hysterometers and vibrating-sample magnetometers. Results. Magnetic hysteresis loops of a bulky ferrite (brand 1SCh4) sample and a 40 μm thick YIG film have been registered using the presented technique and compared with the results obtained by the well-known technique for measuring magnetic hysteresis loops. They are in good agreement with a margin error as low as 10%, which can be further improved by means of more precise equipment. With the presented technique, the magnetization and the coercive force of Fe0.5Co0.5Fe2O4 nanoparticles not examined yet have been determined. Conclusion. The developed technique makes it possible to study magnetic materials of various compositions including nanoscale magnets.

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.

Effects of Magnetic-Field Annealing on the Morphology and Magnetic Properties of La0.7Sr0.3MnO3 Film

2012 ◽  
Vol 170 (5-6) ◽  
pp. 302-306
Author(s):  
Z. F. Zi ◽  
Q. C. Liu ◽  
X. W. Tang ◽  
J. G. Lv ◽  
J. M. Dai ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Properties ◽  
Field Annealing

scholarly journals Developing a reference material set for the magnetic properties of NdFeB alloy-based hard magnetic materials

2019 ◽  
Vol 15 (1) ◽  
pp. 21-27
Author(s):  
E. A. Volegova ◽  
T. I. Maslova ◽  
V. O. Vas’kovskiy ◽  
A. S. Volegov
Keyword(s):  
Magnetic Properties ◽  
Magnetic Materials ◽  
Permanent Magnets ◽  
Magnetic Loss ◽  
Magnetic Hysteresis ◽  
Hysteresis Loops ◽  
Magnetic Hysteresis Loop ◽  
Magnetic Characteristics ◽  
Hard Magnetic Materials ◽  
Certified Values

Introduction The introduction indicates the need for the use of permanent magnets in various technology fields. The necessity of measuring the limit magnetic hysteresis loop for the correct calculation of magnetic system parameters is considered. The main sources of error when measuring boundary hysteresis loops are given. The practical impossibility of verifying blocks of magnetic measuring systems element-by-element is noted. This paper is devoted to the development of reference materials (RMs) for the magnetic properties of hard magnetic materials based on Nd2Fe14B, a highly anisotropic intermetallic compound.Materials and measuring methods Nd-Fe-B permanent magnets were selected as the material for developing the RMs. RM certified values were established using a CYCLE‑3 apparatus included in the GET 198‑2017 State Primary Measurement Standard for units of magnetic loss power, magnetic induction of constant magnetic field in a range from 0.1 to 2.5 T and magnetic flux in a range from 1·10–5 to 3·10–2 Wb.Results and its discussion Based on the experimentally obtained boundary hysteresis loops, the magnetic characteristics were evaluated, the interval of permitted certified values was set, the measurement result uncertainty of certified values was estimated, the RM validity period was established and the first RM batch was released.Conclusion On the basis of conducted studies, the RM type for magnetic properties of NdFeB alloy-based hard magnetic materials was approved (MS NdFeB set). The developed RM set was registered under the numbers GSO 11059–2018 / GSO 11062–2018 in the State RM Register of the Russian Federation.

MAGNETIC PROPERTIES OF THE HIGH Tc SUPERCONDUCTORS BiSrCaCuO AND TlBaCaCuO

1989 ◽  
Vol 03 (01) ◽  
pp. 77-85 ◽  
Author(s):  
Y. D. DAI ◽  
C. LIN ◽  
W. B. ZHANG ◽  
S. Q. FENG ◽  
X. ZHU ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Flux Pinning ◽  
Magnetic Hysteresis ◽  
Hysteresis Loops ◽  
High Tc Superconductors ◽  
Magnetic Current ◽  
High Tc ◽  
Bean Model ◽  
Current Densities ◽  
Magnetic Hysteresis Loops

Magnetic properties of the high T c superconductors BiSrCaCuO and TlBaCaCuO were investigated systematically. Magnetic current densities were calculated from magnetic hysteresis loops of bulk and powdered samples by Bean model. The results showed that flux pinning in these materials is much weaker than that in YBaCuO.

Influence of interdiffusion on the magnetic properties of Co/Si (100) films after high magnetic field annealing

2015 ◽  
Vol 387 ◽  
pp. 6-12 ◽  
Author(s):  
Yue Zhao ◽  
Kai Wang ◽  
Qiang Wang ◽  
Guojian Li ◽  
Changsheng Lou ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Properties ◽  
High Magnetic Field ◽  
Field Annealing

Magnetic Field Annealing Effects on Magnetic Properties of Electrodeposited Co/Cu Multilayered Nanowires

2014 ◽  
Vol 50 (8) ◽  
pp. 1-4 ◽  
Author(s):  
Khalid Javed ◽  
Da Wei Shi ◽  
Syed Shahbaz Ali ◽  
Jun Jiang ◽  
Pan Liu ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Properties ◽  
Annealing Effects ◽  
Field Annealing ◽  
Multilayered Nanowires

High Magnetic Field Annealing of Mn-Ga Intermetallic Alloys

MRS Advances ◽  
2015 ◽  
Vol 1 (3) ◽  
pp. 227-233 ◽  
Author(s):  
Daniel R. Brown ◽  
Ke Han ◽  
Theo Siegrist ◽  
Tiglet Besara ◽  
Rongmei Niu
Keyword(s):  
Magnetic Field ◽  
Heat Treatment ◽  
Magnetic Properties ◽  
Permanent Magnets ◽  
Intermetallic Alloys ◽  
Nanostructured Composite ◽  
Refined Microstructure ◽  
Field Annealing ◽  
High Magnetic Moment ◽  
Hard Magnetic Properties

AbstractMn-Ga alloys have shown promising hard magnetic properties, even though these alloys contain no rare-earth metals. However, much work is needed before Mn-Ga alloys become viable permanent magnets for applications. One of the challenges is to enhance the remanence. One technique to improve this property is applying a magnetic field during the heat treatment process. Magnetic annealing can promote phase transformation of the phases with high magnetic moment. This results in an increased remanence. Bulk samples of Mn-Ga alloys were made by mechanically alloying in order to create a nanostructured composite, followed by heat treatments in the presence of a 31 T magnetic field. The heat treatment temperatures were kept low in order to keep the refined microstructure. All the alloys exhibit hard magnetic properties at room temperature with large coercivity. This work reports findings of magnetic field annealed Mn-Ga bulk that exhibit high coercivities up to 19.4 kOe and increased remanence of 50% over the binary system, achieving values up to 6.9 emu/g. This is the highest coercivity reported in bulk Mn-Ga samples.

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