magnetic devices
Recently Published Documents


TOTAL DOCUMENTS

322
(FIVE YEARS 69)

H-INDEX

24
(FIVE YEARS 6)

2022 ◽  
Author(s):  
Bensaid Djillali ◽  
Doumi Bendouma ◽  
Sohail Ahmad

Abstract Cobalt -rich Heusler compounds represent a very interesting family among Heusler alloys due to their performance in the field of spintronics and magnetic devices. The quaternary Heusler created by swapping of an anti-atom site by an alkali element improves the performance of physical properties for new applications. In this study, the electronic structures and magnetic properties before and after swapping cobalt (Co) by lithium (Li) in the Co2NbAl compound have been investigated using first-principle computational calculations. Our findings revealed that the swapping Co antisite by Li keeps the half-metallic character in the CoLiNbAl. Analysis of band structures show that ternary Heusler compound is ferromagnetic half-metallic with half metallic gap (band gap in minority channel ) equal 0.134 eV but the swapping Co with Li leads the material to change its behavior and becomes a semiconductor with a gap equal 1.043 eV using HSE06 approach. The results of optical and thermoelectric properties such as absorption coefficient, reflectivity or thermopower and figure of merit are very interesting in the optoelectronic field and encourages the researchers to realize photovoltaic cell and thermoelectric generator with a higher efficiency. These interesting features suggest that Co2NbAl and LiNbAlCo Heusler compounds could be good candidates for applications of antiferromagnetic spintronics and optoelectronics in commercial semiconductor industry.


2021 ◽  
Author(s):  
Jun Ren ◽  
Junming Li ◽  
Sheng Zhang ◽  
Jun Li ◽  
Wenxia Su ◽  
...  

Abstract Voltage control magnetism have been widely studied due to their potential applications in the next generation of information technology. PMN-PT, as a single crystal ferroelectric substrate, has been widely used in the study of voltage control magnetism because of its excellent piezoelectric properties. However, most of the research based on PMN-PT only studies the influence of a single tensile (or compressive) stress on the magnetic properties due to the asymmetry of strain. In this work, we show the effect of different strains on the magnetic anisotropy of Fe19Ni81/(011) PMN-PT heterojunction. More importantly, the (011) cut PMN-PT has the characteristics of generating non-volatile strain, which provides the advantage for investigating the voltage manipulation of RF/microwave magnetic devices. As a result, a ferromagnetic resonance field tunability of 70 Oe is induced in our sample by the non-volatile strain. Our results provide new possibilities for novel voltage adjustable RF/microwave magnetic devices and spintronic devices.


Author(s):  
С.И. Корягин ◽  
Н.Л. Великанов ◽  
О.В. Шарков

Оценку технического состояния корпуса судна проводят с применением диагностических датчиков. С помощью них замеряются, например, толщина обшивки, параметры бухтин, вмятин, гофрировки. Процессы эти трудоемкие и достаточно сложные. Проблемой автоматизации таких операций является удержание измерительной аппаратуры на криволинейной поверхности корпуса судна и перемещение аппаратуры по ней. Одним из вариантов решения проблемы является применение подвижных тележек с установленными на них магнитными устройствами. В данной работе исследуются вопросы влияния кривизны обшивки корпуса судна на параметры подвижной магнитной системы. Представлены расчетные схемы для различных компоновок, физические и математические модели. Анализ полученных математических выражений позволил сделать выводы по вариантам размещения, по зазору и скорости его изменения, клиренсу транспортного устройства, углу между опорной поверхностью и торцевой плоскостью магнита, который приводит к уменьшению силы притяжения. Учтен начальный зазор. Проведены расчеты зависимостей изменения радиуса кривизны корпуса судна от колеи и конструктивной схемы мобильных устройств. The assessment of the technical condition of the vessel's hull is carried out using diagnostic sensors. They are used to measure, for example, the thickness of the skin, the parameters of camber, dents, corrugations. These processes are time-consuming and quite complex. The problem of automation of such operations is the retention of measuring equipment on the curved surface of the hull of the vessel and the movement of equipment along it. One of the solutions to the problem is the use of movable trolleys with magnetic devices installed on them. In this paper, the issues of the influence of the curvature of the hull covering on the parameters of the mobile magnetic system are investigated. Calculation schemes for various layouts, physical and mathematical models are presented. The analysis of the obtained mathematical expressions allowed us to draw conclusions on the placement options, on the gap and the speed of its change, the clearance of the transport device, the angle between the support surface and the end plane of the magnet, which leads to a decrease in the force of attraction. The initial gap is taken into account. Calculations of the dependences of changes in the radius of curvature of the hull of the vessel on the track and the design scheme of mobile devices are carried out.


2021 ◽  
Vol 5 (1) ◽  
Author(s):  
Wei-En Ke ◽  
Pao-Wen Shao ◽  
Chang-Yang Kuo ◽  
Haili Song ◽  
Rong Huang ◽  
...  

AbstractRecent advances in the design and development of magnetic storage devices have led to an enormous interest in materials with perpendicular magnetic anisotropy (PMA) property. The past decade has witnessed a huge growth in the development of flexible devices such as displays, circuit boards, batteries, memories, etc. since they have gradually made an impact on people’s lives. Thus, the integration of PMA materials with flexible substrates can benefit the development of flexible magnetic devices. In this study, we developed a heteroepitaxy of BaFe12O19 (BaM)/muscovite which displays both mechanical flexibility and PMA property. The particular PMA property was characterized by vibrating sample magnetometer, magnetic force microscopy, and x-ray absorption spectroscopy. To quantify the PMA property of the system, the intrinsic magnetic anisotropy energy density of ~2.83 Merg cm−3 was obtained. Furthermore, the heterostructure exhibits robust PMA property against severe mechanical bending. The findings of this study on the BaM/muscovite heteroepitaxy have several important implications for research in next-generation flexible magnetic recording devices and actuators.


Author(s):  
Roman Krumpholz ◽  
Jonas Fuchtmann ◽  
Maximilian Berlet ◽  
Annika Hangleiter ◽  
Daniel Ostler ◽  
...  

Abstract Purpose While demand for telemedicine is increasing, patients are currently restricted to tele-consultation for the most part. Fundamental diagnostics like the percussion still require the in person expertize of a physician. To meet today’s challenges, a transformation of the manual percussion into a standardized, digital version, ready for telemedical execution is required. Methods In conjunction with a comprehensive telemedical diagnostic system, in which patients can get examined by a remote-physician, a series of three robotic end-effectors for mechanical percussion were developed. Comprising a motor, a magnetic and a pneumatic-based version, the devices strike a pleximeter to perform the percussion. Emitted sounds were captured using a microphone-equipped stethoscope. The 84 recordings were further integrated into a survey in order to classify lung and non-lung samples. Results The study with 21 participants comprised physicians, medical students and non-medical-related raters in equal parts. With 71.4% correctly classified samples, the ventral motorized device prevailed. While the result is significantly better compared to a manual or pneumatic percussion in this very setup, it only has a small edge over the magnetic devices. In addition, for all ventral versions non-lung regions were rather correctly identified than lung regions. Conclusion The overall setup proves the feasibility of a telemedical percussion. Despite the fact, that produced sounds differ compared to today’s manual technique, the study shows that a standardized mechanical percussion has the potential to improve the gold standard’s accuracy. While further extensive medical evaluation is yet to come, the system paves the way for future uncompromised remote examinations.


2021 ◽  
Vol 926 (1) ◽  
pp. 012040
Author(s):  
A Indriawati ◽  
R Sari ◽  
Sulanjari

Abstract The development of spintronic devices in the magnetic memories industry has attracted researchers over decades. Therefore, researchers are trying to obtain materials which compatible to improve device performance. These materials are made in the form of thin layer. Cerium-iron-boron (Ce-Fe-B) alloy is one of potential materials to be applied for magnetic devices. In this study, the nucleation changes in the Ce-Fe-B thin layer were analyzed using circular and rectangular shapes. This phenomenon was observed through micromagnetic simulations. The magnetic moment stability of Ce-Fe-B was analyzed based on the response of the magnetic moment towards the presence of an external magnetic field. The magnitude of applied external magnetic applied is 0.4 Tesla in x-axis direction. Changes in the arrangement of magnetic moments due to external magnetic fields produce magnetization and anisotropy energy value which describing the characteristics of the Ce-FeB thin layer. Magnetization value of Ce-Fe-B thin film in circular shape was greather than rectangular shape. These value was 0.98 for circular shape and 0.93 for rectangular shape. On the other hand, anisotropy energy value on magnetic external apllied 400 mT, circular shape anisotropy energy’s value of Ce-Fe-B was 4.85×10-18 J, and 6.71×10-18 J for rectangular shape.


2021 ◽  
Author(s):  
Scott D. Sudhoff
Keyword(s):  

Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6498
Author(s):  
Fabio Corti ◽  
Alberto Reatti ◽  
Gabriele Maria Lozito ◽  
Ermanno Cardelli ◽  
Antonino Laudani

In this paper, the problem of estimating the core losses for inductive components is addressed. A novel methodology is applied to estimate the core losses of an inductor in a DC-DC converter in the time-domain. The methodology addresses both the non-linearity and dynamic behavior of the core magnetic material and the non-uniformity of the field distribution for the device geometry. The methodology is natively implemented using the LTSpice simulation environment and can be used to include an accurate behavioral model of the magnetic devices in a more complex lumped circuit. The methodology is compared against classic estimation techniques such as Steinmetz Equation and the improved Generalized Steinmetz Equation. The validation is performed on a practical DC-DC Buck converter, which was utilized to experimentally verify the results derived by a model suitable to estimate the inductor losses. Both simulation and experimental test confirm the accuracy of the proposed methodology. Thus, the proposed technique can be flexibly used both for direct core loss estimation and the realization of a subsystem able to simulate the realistic behavior of an inductor within a more complex lumped circuit.


Coatings ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1209
Author(s):  
Dung Nguyen Trong ◽  
Van Cao Long ◽  
Ştefan Ţălu

In this paper, the study of the influence of the matrix structure (mxm) of thin-film, rotation angle (α), magnetic field (B), and size (D) of Fe2O3 nanoparticle on the magnetic characteristic quantities such as the magnetization oriented z-direction (MzE), z-axis magnetization (Mz), total magnetization (Mtot), and total entropy (Stot) of Fe2O3 nanocomposites by Monte-Carlo (MC) simulation method are studied. The applied MC Metropolis code achieves stability very quickly, so that after 30 Monte Carlo steps (MCs), the change of obtained results is negligible, but for certainty, 84 MCs have been performed. The obtained results show that when the mxm and α increase, the magnetic phase transition appears with a very small increase in temperature Néel (TNtot). When B and D increase, TNtot increases very strongly. The results also show that in Fe2O3 thin films, TNtot is always smaller than with Fe2O3 nano and Fe2O3 bulk. When the nanoparticle size is increased to nearly 12 nm, then TNtot = T = 300 K, and between TNtot and D, there is a linear relationship: TNtot = −440.6 + 83D. This is a very useful result that can be applied in magnetic devices and in biomedical applications.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Zhuolin Li ◽  
Jian Su ◽  
Shi-Zeng Lin ◽  
Dan Liu ◽  
Yang Gao ◽  
...  

AbstractExploring and controlling topological textures such as merons and skyrmions has attracted enormous interests from the perspective of fundamental research and spintronic applications. It has been predicted theoretically and proved experimentally that the lattice form of topological meron-skyrmion transformation can be realized with the requirement of external magnetic fields in chiral ferromagnets. However, such topological transition behavior has yet to be verified in other materials. Here, we report real-space observation of magnetic topology transformation between meron pairs and skyrmions in the localized domain wall of ferrimagnetic GdFeCo films without the need of magnetic fields. The topological transformation in the domain wall of ferrimagnet is introduced by temperature-induced spin reorientation transition (SRT) and the underlying mechanism is revealed by micromagnetic simulations. The convenient electric-controlling topology transformation and driving motion along the confined domain wall is further anticipated, which will enable advanced application in magnetic devices.


Sign in / Sign up

Export Citation Format

Share Document