Characteristic Features of Magnetization Reversal of Exchange Coupled Tb–Co/FeNi Film Structures in a Temperature Range Including the Compensation Point of the Ferrimagnetic Layer

2021 ◽  
Author(s):  
A. V. Svalov ◽  
V. N. Lepalovskii ◽  
E. A. Stepanova ◽  
I. A. Makarochkin ◽  
V. O. Vas’kovskii ◽  
...  
Keyword(s):  
Magnetization Reversal ◽  
Compensation Point ◽  
Temperature Range ◽  
Characteristic Features

scholarly journals Subsystem domination influence on magnetization reversal in designed magnetic patterns in ferrimagnetic Tb/Co multilayers

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Łukasz Frąckowiak ◽  
Feliks Stobiecki ◽  
Gabriel David Chaves-O’Flynn ◽  
Maciej Urbaniak ◽  
Marek Schmidt ◽  
...  
Keyword(s):  
Domain Wall ◽  
Magnetization Reversal ◽  
Domain Walls ◽  
Compensation Point ◽  
Relative Sign ◽  
Reversal Process ◽  
Effective Magnetization ◽  
Domain Wall Propagation ◽  
Characteristic Features ◽  
Magnetization Reversal Process

AbstractRecent results showed that the ferrimagnetic compensation point and other characteristic features of Tb/Co ferrimagnetic multilayers can be tailored by He+ ion bombardment. With appropriate choices of the He+ ion dose, we prepared two types of lattices composed of squares with either Tb or Co domination. The magnetization reversal of the first lattice is similar to that seen in ferromagnetic heterostructures consisting of areas with different switching fields. However, in the second lattice, the creation of domains without accompanying domain walls is possible. These domain patterns are particularly stable because they simultaneously lower the demagnetizing energy and the energy associated with the presence of domain walls (exchange and anisotropy). For both lattices, studies of magnetization reversal show that this process takes place by the propagation of the domain walls. If they are not present at the onset, the reversal starts from the nucleation of reversed domains and it is followed by domain wall propagation. The magnetization reversal process does not depend significantly on the relative sign of the effective magnetization in areas separated by domain walls.

scholarly journals Особенности перемагничивания обменно-связанных пленочных структур Tb-Co/FeNi в температурном интервале, включающем точку компенсации ферримагнитного слоя

2021 ◽  
Vol 63 (9) ◽  
pp. 1198
Author(s):  
А.В. Свалов ◽  
В.Н. Лепаловский ◽  
Е.А. Степанова ◽  
И.А. Макарочкин ◽  
В.О. Васьковский ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Magnetron Sputtering ◽  
Exchange Interaction ◽  
Wide Temperature Range ◽  
Magnetization Reversal ◽  
Compensation Temperature ◽  
Zeeman Energy ◽  
Temperature Range ◽  
Interlayer Exchange

The magnetic properties of exchange-coupled Tb-Co/FeNi film structures obtained by magnetron sputtering were studied in a wide temperature range. It was shown that a decrease in the Zeeman energy when approaching the compensation temperature of the ferrimagnetic layer was accompanied by a change in the sequence of magnetization reversal of the layers. The efficiency of the interlayer exchange interaction varies with temperature very little.

Effect of Interaction in the Magnetization Reversal Relaxation of Superparamagnetic Granular CoFeB -SiO2 Films

2009 ◽  
Vol 152-153 ◽  
pp. 213-216 ◽  
Author(s):  
A.A. Timopheev ◽  
S.M. Ryabchenko ◽  
V.M. Kalita ◽  
A.F. Lozenko ◽  
P.A. Trotsenko ◽  
...  
Keyword(s):  
Magnetization Reversal ◽  
Magnetic Interactions ◽  
Blocking Temperature ◽  
Relaxation Processes ◽  
Measuring Time ◽  
Temperature Range ◽  
Simulation Based ◽  
Temperature Dependences ◽  
Inclination Angles ◽  
Superparamagnetic State

In order to study the magnetic interactions influence on the relaxation processes in superparamagnetic media, the magnetostatic measurements were carried out for the granular (CoFeB)x-(SiO2)1-x films with x values near percolation threshold. The observed temperature dependences of the coercivity for the samples magnetized along in-plane easy axis have shown two parts linear on with different inclination angles, which cross each other at the blocking temperature (Tb). The first part of the curve, which corresponds to the temperature range below Tb, depends on the measuring time and is related to the thermal activation nature of magnetization reversal process in the blocked superparamagnetic state. Second part of the curve, which corresponds to the temperature range above Tb, is practically independent on the measuring time and is related to existence of correlated state of superparamagnetic grains moments, i.e. to superferromagnetic state. The method of the magnetization reversal curves simulation based on the numerical solving of kinetic equation has been applied to explain the experimental results.

scholarly journals Half-metallic compensated ferrimagnetism with a tunable compensation point over a wide temperature range in the Mn-Fe-V-Al Heusler system

AIP Advances ◽  
2017 ◽  
Vol 7 (10) ◽  
pp. 105009 ◽  
Author(s):  
Rolf Stinshoff ◽  
Gerhard H. Fecher ◽  
Stanislav Chadov ◽  
Ajaya K. Nayak ◽  
Benjamin Balke ◽  
...  
Keyword(s):  
Wide Temperature Range ◽  
Compensation Point ◽  
Half Metallic ◽  
Temperature Range

scholarly journals Influence of Magnetic Prehistory on the Exchange Bias in Fe20Ni80/FeMn/Fe20Ni80 Films

2016 ◽  
Vol 1 (1) ◽  
pp. 84
Author(s):  
T.V. Kulikova ◽  
E.A. Stepanova ◽  
V.O. Vas’kovskiy
Keyword(s):  
Magnetization Reversal ◽  
Exchange Bias ◽  
Temperature Range ◽  
Hysteresis Properties

<p>In this work peculiarities of the hysteresis properties formation in permalloy layers included in Fe<sub>20</sub>Ni<sub>80</sub>/FeMn/Fe<sub>20</sub>Ni<sub>80</sub> films were investigated. Temperature dependencies of magnetization reversal parameters were analyzed in the temperature range 5-300 K for samples with various FeMn thickness (2÷4 nm). Conditions of the exchange bias emergence were determined. Magnetic history was shown to have a significant effect on the magnitude and the character of the exchange bias.</p>

scholarly journals Особенности импульсного перемагничивания высококоэрцитивного материала на основе наночастиц ε-Fe-=SUB=-2-=/SUB=-O-=SUB=-3-=/SUB=-

2020 ◽  
Vol 62 (3) ◽  
pp. 395
Author(s):  
С.И. Попков ◽  
А.А. Красиков ◽  
С.В. Семенов ◽  
А.А. Дубровский ◽  
С.С. Якушкин ◽  
...  
Keyword(s):  
Iron Oxide ◽  
Coercive Force ◽  
Magnetic Structure ◽  
Magnetization Reversal ◽  
Room Temperature ◽  
Polymorphic Modification ◽  
Fe2o3 Nanoparticles ◽  
Temperature Range ◽  
Dynamic Magnetization ◽  
Static Conditions

The magnetic structure of the polymorphic modification of iron oxide ε-Fe2O3 is collinear ferrimagnetic in the range from room temperature to ~ 150 K. Further, with decreasing a temperature in ε-Fe2O3, a magnetic transition occurs, accompanied by a significant decrease in the coercive force HC, and in the low temperature range ε-Fe2O3 is characterized by a complex incommensurate magnetic structure. In this work, we experimentally investigated the processes of dynamic magnetization reversal of ε-Fe2O3 nanoparticles of an average size of 8 nm in the temperature range of 80–300 K, comprising various types of magnetic structure of this iron oxide. A bulk material was studied - xerogel SiO2 with ε Fe2O3 nanoparticles embedded in pores. To measure the magnetic hysteresis loops under dynamic magnetization reversal, a pulsed magnetic field technique of Hmax up to 130 kOe was used, using the method of discharging a capacitor bank through a solenoid. The coercive force of HC during dynamic magnetization reversal noticeably exceeds HC for quasi-static conditions. This is caused by processes of superparamagnetic relaxation of the magnetic moments of particles during pulsed magnetization reversal. In the range from room temperature to ~ 150 K, the rate of change of the external field dH / dt is the main parameter determining the behavior of the coercive force under the conditions of dynamic magnetization reversal. This behavior is expected for a system of single-domain ferro- and ferrimagnetic particles. Under external conditions (at a temperature of 80 K), when the magnetic structure of ε Fe2O3 is incommensurate, the coercive force during pulsed magnetization reversal already depends on the parameter dH / dt, and is largely determined by the maximum applied field Hmax. Such a behavior, atypical for systems of ferrimagnetic particles, is already caused by dynamic spin processes inside ε-Fe2O3 particles during fast magnetization reversal.

Weak ferrimagnetism, compensation point, and magnetization reversal inNi(HCOO)2⋅2H2O

2003 ◽  
Vol 67 (22) ◽  
Author(s):  
H. Kageyama ◽  
D. I. Khomskii ◽  
R. Z. Levitin ◽  
A. N. Vasil’ev
Keyword(s):  
Magnetization Reversal ◽  
Compensation Point

Ultrastructural modification of cellular interactions in cancer tumor

1978 ◽  
Vol 36 (2) ◽  
pp. 318-319
Author(s):  
N. P. Dmitrieva
Keyword(s):  
Cancer Cells ◽  
Human Thyroid ◽  
Adjacent Cell ◽  
Main Role ◽  
Cellular Interactions ◽  
Electron Microscopic ◽  
Cancer Tumor ◽  
Normal Human ◽  
Characteristic Features

One of the most characteristic features of cancer cells is their ability to metastasia. It is suggested that the modifications of the structure and properties of cancer cells surfaces play the main role in this process. The present work was aimed at finding out what ultrastructural features apear in tumor in vivo which removal of individual cancer cells from the cell population can provide. For this purpose the cellular interactions in the normal human thyroid and cancer tumor of this gland electron microscopic were studied. The tissues were fixed in osmium tetroxide and were embedded in Araldite-Epon.In normal human thyroid the most common type of intercellular contacts was represented by simple junction formed by the parallelalignment of adjacent cell membranees leaving in between an intermembranes space 15-20 nm filled with electronlucid material (Fig. 1a). Sometimes in the basal part of cells dilatations of the intercellular space 40-50 nm wide were found (Fig. 1a). Here the cell surfaces may form single short microvilli.

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