Study of the iron nanoparticles phase transformation during thermal annealing

Change in structural properties and phase composition of nanoparticles based on iron oxide was researched in the paper. As a result of conducted studies it was found that during heat treatment oxide phases of (γ-Fe2O3) and α-Fe2O3 maghemite were formed in oxygen atmosphere. Researches of powder array magnetization were showed that the hysteresis loop movement had the form characteristic for ferromagnetic materials. Additionally, loops obtained at different directions of the magnetic field have different characters, which indicate the magnetic anisotropy presence in the samples.

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Experimental Analysis of Ratcheting Failure Based on the Piezomagnetic Response of X80 Pipeline Steel

Volume 4: Materials Technology ◽

10.1115/omae2017-62170 ◽

2017 ◽

Author(s):

Sheng Bao ◽

Shengnan Hu ◽

Yibin Gu

Keyword(s):

Magnetic Field ◽

Hysteresis Loop ◽

Mechanical Response ◽

Pipeline Steel ◽

Failure Process ◽

Failure Behavior ◽

X80 Pipeline Steel ◽

Test Analysis ◽

Number Of Cycles ◽

The Magnetic Field

The objective of this research is to explore the correlation between the piezomagnetic response and ratcheting failure behavior under asymmetrical cyclic stressing in X80 pipeline steel. The magnetic field variations from cycle to cycle were recorded simultaneously during the whole-life ratcheting test. Analysis made in the present work shows that the piezomagnetic hysteresis loop evolves systematically with the number of cycles in terms of its shape and position. Corresponding to the three-stage process in the mechanical response, piezomagnetic response can also be divided into three principal stages, but the evolution of magnetic parameter is more complex. Furthermore, the loading branch and unloading branch of the magnetic field-stress hysteresis loop separate gradually from each other during ratcheting failure process, leading to the shape of hysteresis loop changes completely. Therefore, the progressive degradation of the steel under ratcheting can be tracked by following the evolution of the piezomagnetic field. And the shape transition of the hysteresis loop can be regarded as an early warning of the ratcheting failure.

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The Magnetic Anisotropy of Stretched Rubber as a Function of the Tension to Which It Is Subjected

Rubber Chemistry and Technology ◽

10.5254/1.3543206 ◽

1945 ◽

Vol 18 (1) ◽

pp. 8-9 ◽

Cited By ~ 1

Author(s):

Eugénie Cotton-Feytis

Keyword(s):

Magnetic Field ◽

Magnetic Anisotropy ◽

Uniaxial Crystal ◽

Horizontal Magnetic Field ◽

First Approximation ◽

The Difference ◽

The Times ◽

Angular Displacements ◽

The Magnetic Field ◽

Oscillation Method

Abstract From the standpoint of its magnetic anisotropy, stretched rubber is comparable in a first approximation to a uniaxial crystal, in which the direction of the axis is the same as the direction of elongation. It is possible to measure this anisotropy by means of the oscillation method used by Krishnan, Guha and Banerjee in studying crystals. The sample to be examined is suspended in a uniform horizontal magnetic field in such a manner that its axis is horizontal. It is then so arranged that the torsion of the suspension wire is zero when the rubber sample is in a position of equilibrium in the field. The times of oscillation T′ and T for very small angular displacements around this position, in the presence and then in the absence of the magnetic field, are then recorded. In this way the difference between the specific susceptibilities in the direction of the axis and in the horizontal direction perpendicular to the axis is calculated by application of the equation:

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

Textures and Microstructures ◽

10.1155/tsm.32.289 ◽

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.

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Magnetic Field-Assisted Chemical Vapor Deposition of Iron Oxide Thin Films: Influence of Field–Matter Interactions on Phase Composition and Morphology

The Journal of Physical Chemistry Letters ◽

10.1021/acs.jpclett.9b02381 ◽

2019 ◽

Vol 10 (20) ◽

pp. 6253-6259 ◽

Cited By ~ 4

Author(s):

Daniel Stadler ◽

David N. Mueller ◽

Thomas Brede ◽

Tomáš Duchoň ◽

Thomas Fischer ◽

...

Keyword(s):

Magnetic Field ◽

Thin Films ◽

Phase Composition ◽

Chemical Vapor Deposition ◽

Iron Oxide ◽

Vapor Deposition ◽

Chemical Vapor ◽

Oxide Thin Films

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Recent Developments of Magnetic SMA

Advances in Science and Technology ◽

10.4028/www.scientific.net/ast.59.1 ◽

2008 ◽

Vol 59 ◽

pp. 1-10 ◽

Cited By ~ 8

Author(s):

Outi Söderberg ◽

Ilkka Aaltio ◽

Yan Ling Ge ◽

Xu Wen Liu ◽

Simo Pekka Hannula

Keyword(s):

Magnetic Field ◽

Phase Transformation ◽

Shape Memory ◽

Dimensional Change ◽

Magnetic Shape Memory ◽

Dimensional Changes ◽

Different Types ◽

Recent Developments ◽

Giant Magnetocaloric Effect ◽

The Magnetic Field

In the shape memory alloys (SMAs) the thermal triggering induces reversible dimensional change by the phase transformation – these materials may also be ferrior ferromagnetic, however, here only the ferromagnetic SMAs are discussed. In certain SMAs the austenitemartensite phase transformation is influenced by the magnetic field as either austenite or martensite is promoted by the field and this is exploited for the dimensional changes. However, in the magnetic shape memory (MSM) alloys no phase transformation occurs as the remarkable dimensional changes take place by the twin variant changes in the martensitic phase activated by the external magnetic field at constant temperature. In addition to the phase transformation or magnetic shape memory effect, the applied magnetic field may also result in the conventional magnetostriction (MS), enhance the superelasticity (magneticfieldassisted superelasticity MFAS) or induce the giant magnetocaloric effect (GMCE). Certain alloys such as NiMnGa may even be multifunctional showing more than one of these effects. The present paper gives an overview of the different types of the magnetically activated SMA alloys, their properties as well as their potentials for applications in the frameworks of the recent studies.

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Effect of the magnetic field in the plane of a garnet ferrite film with orthorhombic magnetic anisotropy on the dynamics of domain walls

Physics of the Solid State ◽

10.1134/1.1562238 ◽

2003 ◽

Vol 45 (3) ◽

pp. 503-507 ◽

Cited By ~ 1

Author(s):

V. V. Randoshkin ◽

V. A. Polezhaev ◽

N. N. Sysoev ◽

Yu. N. Sazhin ◽

V. N. Dudorov

Keyword(s):

Magnetic Field ◽

Magnetic Anisotropy ◽

Domain Walls ◽

Ferrite Film ◽

Garnet Ferrite ◽

The Magnetic Field

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Pressure Dependence of the de Haas – van Alphen Effect in Ytterbium

Canadian Journal of Physics ◽

10.1139/p74-211 ◽

1974 ◽

Vol 52 (17) ◽

pp. 1622-1627 ◽

Cited By ~ 14

Author(s):

A. J. Slavin ◽

W. R. Datars

Keyword(s):

Magnetic Field ◽

Phase Transition ◽

Phase Transformation ◽

Pressure Dependence ◽

Experimental Error ◽

Solid Helium ◽

Field Direction ◽

Magnetic Field Direction ◽

Pressure Medium ◽

The Magnetic Field

The de Haas–van Alphen effect and the h.c.p.–f.c.c. phase transformation of ytterbium were studied with the magnetic field along the [0001] direction in the h.c.p. phase, using pressures up to 4 kbar. Solid helium was used as the pressure medium. The pressure dependence of the three dHvA frequencies in the h.c.p. phase for the [0001] magnetic field direction was linear within experimental error with dF/dP = −1.2 ± 0.2 T/kbar for F(P = 0) of 35.4 T, dF/dP = 0.30 ± 0.03 T/kbar for F(P = 0) of 142.5 T, and dF/dP = −0.78 ± 0.10 T/kbar for F(P = 0) of 156.4 T. The dHvA amplitude in the h.c.p. phase was independent of pressure up to the phase transition and no dHvA effect was observed in the f.c.c. phase. The pressure of the phase transformation at 1.2 K was determined to be 2.15 ± 0.05 kbar.

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