Efficiency of Magnetostatic Protection Using Nanostructured Permalloy Shielding Coatings Depending on Their Microstructure

The effect of microstructure on the efficiency of shielding or shunting of the magnetic flux by permalloy shields was investigated in the present work. For this purpose, the FeNi shielding coatings with different grain structures were obtained using stationary and pulsed electrodeposition. The coatings’ composition, crystal structure, surface microstructure, magnetic domain structure, and shielding efficiency were studied. It has been shown that coatings with 0.2–0.6 µm grains have a disordered domain structure. Consequently, a higher value of the shielding efficiency was achieved, but the working range was too limited. The reason for this is probably the hindered movement of the domain boundaries. Samples with nanosized grains have an ordered two-domain magnetic structure with a permissible partial transition to a superparamagnetic state in regions with a grain size of less than 100 nm. The ordered magnetic structure, the small size of the domain, and the coexistence of ferromagnetic and superparamagnetic regions, although they reduce the maximum value of the shielding efficiency, significantly expand the working range in the nanostructured permalloy shielding coatings. As a result, a dependence between the grain and domain structure and the efficiency of magnetostatic shielding was found.

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On the Formation of High Damping State in Fe-Al and Fe-Cr Alloys

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.137.109 ◽

2008 ◽

Vol 137 ◽

pp. 109-118 ◽

Cited By ~ 1

Author(s):

I.B. Chudakov ◽

Nataly A. Polyakova ◽

S.Yu. Mackushev ◽

V.A. Udovenko

Keyword(s):

Domain Structure ◽

Domain Walls ◽

Volume Fraction ◽

Magnetic Domain ◽

Al Alloys ◽

The State ◽

Magnetic Domain Structure ◽

Damping Capacity ◽

Domain Structures ◽

Domain Boundaries

High damping Fe - Cr and Fe - Al alloys have been studied in two different states: in the high damping state and in the suppressed damping capacity state. It has been shown that magnetic domain structures of Fe - Cr and Fe - Al alloys are fundamentally different in the high damping state and in the state with the suppressed damping. Magnetic domain structure corresponding to the high damping state can be characterized by an enhanced volume fraction of the easy movable 90o-domain walls, but the state with the suppressed damping capacity can be characterized by the enhanced volume fraction of the 180o-domain boundaries.

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The Influence of Magnetoelectric Interactions on the Domain Walls in Multiferroics

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.190.265 ◽

2012 ◽

Vol 190 ◽

pp. 265-268

Author(s):

Z.V. Gareeva ◽

A.K. Zvezdin

Keyword(s):

Magnetic Structure ◽

Domain Structure ◽

Domain Walls ◽

Magnetic Domain ◽

Ferroelectric Domain ◽

Domain Pattern ◽

Ferroelectric Domains ◽

Magnetic Domain Walls ◽

Vector Distribution ◽

Antiferromagnetic Vector

The influence of magnetoelectric interactions on the magnetic structure, flexomagnetoelectric polarization and magnetization in thin multiferroics film has been investigated. The correlation between antiferromagnetic domain structure and ferroelectric domain pattern has been revealed. It has been shown the asymmetry of the antiferromagnetic vector distribution over multiferroics film in the case of 1090 and 710 ferroelectric domain walls. The direction of spins rotation in magnetic domain walls is determined by the type of ferroelectric domains and the antiferromagnetic vector in the centre of ferroelectric domain. The peculiarities of the micromagnetic distribution are reflected in the behavior of polarization and magnetization, which appears to be different for 1800, 1090 and 710 ferroelectric domains.

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Domains and domain nucleation in magnetron-sputtered CoCr thin films

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100151064 ◽

1993 ◽

Vol 51 ◽

pp. 1046-1047

Author(s):

B. G. Demczyk

Keyword(s):

Thin Films ◽

Domain Structure ◽

Magnetic Domain ◽

Domain Size ◽

Film Plane ◽

Magnetic Domain Structure ◽

Perpendicular Magnetization ◽

Columnar Grains ◽

Reversal Mechanism ◽

Lorentz Transmission Electron Microscopy

CoCr thin films have been of interest for a number of years due to their strong perpendicular anisotropy, favoring magnetization normal to the film plane. The microstructure and magnetic properties of CoCr films prepared by both rf and magnetron sputtering have been examined in detail. By comparison, however, relatively few systematic studies of the magnetic domain structure and its relation to the observed film microstructure have been reported. In addition, questions still remain as to the operative magnetization reversal mechanism in different film thickness regimes. In this work, the magnetic domain structure in magnetron sputtered Co-22 at.%Cr thin films of known microstructure were examined by Lorentz transmission electron microscopy. Additionally, domain nucleation studies were undertaken via in-situ heating experiments.It was found that the 50 nm thick films, which are comprised of columnar grains, display a “dot” type domain configuration (Figure 1d), characteristic of a perpendicular magnetization. The domain size was found to be on the order of a few structural columns in diameter.

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Magnetic Domain Structure of Heat-Resistant Domain-Refined Grain-Oriented Silicon Steel Sheet

IEEJ Transactions on Fundamentals and Materials ◽

10.1541/ieejfms.134.105 ◽

2014 ◽

Vol 134 (2) ◽

pp. 105-109

Author(s):

Tadashi Nakanishi ◽

Masayoshi Ishida

Keyword(s):

Domain Structure ◽

Steel Sheet ◽

Magnetic Domain ◽

Silicon Steel ◽

Magnetic Domain Structure ◽

Heat Resistant

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Influence of the magnetic domain structure in the mass sensitivity of magnetoelastic sensors with different geometries

Journal of Alloys and Compounds ◽

10.1016/j.jallcom.2020.158555 ◽

2021 ◽

Vol 863 ◽

pp. 158555

Author(s):

Paula G. Saiz ◽

Jose M. Porro ◽

Andoni Lasheras ◽

Roberto Fernández de Luis ◽

Iban Quintana ◽

...

Keyword(s):

Domain Structure ◽

Magnetic Domain ◽

Magnetic Domain Structure ◽

Mass Sensitivity ◽

Magnetoelastic Sensors

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Formulation of Quaternized Aminated Chitosan Nanoparticles for Efficient Encapsulation and Slow Release of Curcumin

Molecules ◽

10.3390/molecules26020449 ◽

2021 ◽

Vol 26 (2) ◽

pp. 449

Author(s):

Ahmed M. Omer ◽

Zyta M. Ziora ◽

Tamer M. Tamer ◽

Randa E. Khalifa ◽

Mohamed A. Hassan ◽

...

Keyword(s):

Slow Release ◽

Sodium Tripolyphosphate ◽

Chitosan Nanoparticles ◽

Gastric Fluid ◽

Release Profile ◽

Simulated Gastric Fluid ◽

Maximum Value ◽

Structure Surface ◽

Drug Encapsulation Efficiency

An effective drug nanocarrier was developed on the basis of a quaternized aminated chitosan (Q-AmCs) derivative for the efficient encapsulation and slow release of the curcumin (Cur)-drug. A simple ionic gelation method was conducted to formulate Q-AmCs nanoparticles (NPs), using different ratios of sodium tripolyphosphate (TPP) as an ionic crosslinker. Various characterization tools were employed to investigate the structure, surface morphology, and thermal properties of the formulated nanoparticles. The formulated Q-AmCs NPs displayed a smaller particle size of 162 ± 9.10 nm, and higher surface positive charges, with a maximum potential of +48.3 mV, compared to native aminated chitosan (AmCs) NPs (231 ± 7.14 nm, +32.8 mV). The Cur-drug encapsulation efficiency was greatly improved and reached a maximum value of 94.4 ± 0.91%, compared to 75.0 ± 1.13% for AmCs NPs. Moreover, the in vitro Cur-release profile was investigated under the conditions of simulated gastric fluid [SGF; pH 1.2] and simulated colon fluid [SCF; pH 7.4]. For Q-AmCs NPs, the Cur-release rate was meaningfully decreased, and recorded a cumulative release value of 54.0% at pH 7.4, compared to 73.0% for AmCs NPs. The formulated nanoparticles exhibited acceptable biocompatibility and biodegradability. These findings emphasize that Q-AmCs NPs have an outstanding potential for the delivery and slow release of anticancer drugs.

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