scholarly journals Asymmetric Hysteresis Modeling Approach Featuring “Inertial System + Shape Function” for Magnetostrictive Actuators

Materials ◽  
2020 ◽  
Vol 13 (11) ◽  
pp. 2585
Author(s):  
Zhi-Yuan Si ◽  
Xian-Xu ‘Frank’ Bai ◽  
Li-Jun Qian
Keyword(s):  
Domain Walls ◽  
Shape Function ◽  
Dead Zone ◽  
Inertial System ◽  
Hysteresis Model ◽  
Magnetic Domains ◽  
Application Systems ◽  
Magnetostrictive Materials ◽  
Magnetostrictive Actuators ◽  
Hysteresis Characteristics

Hysteresis of the actuators based on magnetostrictive materials influences the control performance of the application systems. It is of importance and significance to establish an effective hysteresis model for the magnetostrictive actuators for precision engineering. In this paper, based on the analysis of the Duhem model, a first-order inertial system with hysteresis characteristic under harmonic input is used to describe the hysteresis caused by the inertia of the magnetic domains of magnetostrictive materials. Shape function is employed to describe the pinning of domain walls, the interactions of different magnetic domains of magnetostrictive materials, and the saturation properties of the hysteresis. Specifically, under an architecture of “inertial system + shape function” (ISSF-Duhem model), firstly a new hysteresis model is proposed for magnetostrictive actuators. The formulation of the inertial system is constructed based on its general expression, which is capable of describing the hysteresis characteristics of magnetostrictive actuators. Then, the developed models with a Grompertz function-based shape function, a modified hyperbolic tangent function-based shape function employing an exponential function as an offset function, a one-sided dead-zone operator-based shape function are compared with each other, and further compared with the classic modified Prandtl–Ishlinskii model with a one-sided dead-zone operator. Sequentially, feasibility and capability of the proposed hysteresis model are verified and evaluated by describing and predicting the hysteresis characteristics of a commercial magnetostrictive actuator.

Lorentz microscopy study of magnetic domain walls in Fe-Cr-Co alloys

1978 ◽  
Vol 36 (1) ◽  
pp. 462-463
Author(s):  
Yalcin Belli
Keyword(s):  
Domain Walls ◽  
Magnetic Domain ◽  
Microscopy Study ◽  
Ferromagnetic Phase ◽  
Stable Phase ◽  
Magnetic Domains ◽  
Lorentz Microscopy ◽  
Magnetic Hardening ◽  
Electron Microscopes ◽  
Co Alloys

Fe-Cr-Co alloys have great technological potential to replace Alnico alloys as hard magnets. The relationship between the microstructures and the magnetic properties has been recently established for some of these alloys. The magnetic hardening has been attributed to the decomposition of the high temperature stable phase (α) into an elongated Fe-rich ferromagnetic phase (α1) and a weakly magnetic or non-magnetic Cr-rich phase (α2). The relationships between magnetic domains and domain walls and these different phases are yet to be understood. The TEM has been used to ascertain the mechanism of magnetic hardening for the first time in these alloys. The present paper describes the magnetic domain structure and the magnetization reversal processes in some of these multiphase materials. Microstructures to change properties resulting from, (i) isothermal aging, (ii) thermomagnetic treatment (TMT) and (iii) TMT + stepaging have been chosen for this investigation. The Jem-7A and Philips EM-301 transmission electron microscopes operating at 100 kV have been used for the Lorentz microscopy study of the magnetic domains and their interactions with the finely dispersed precipitate phases.

scholarly journals Hysteresis Modeling and Compensation of Fast Steering Mirrors with Hysteresis Operator Based Back Propagation Neural Networks

Micromachines ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 732
Author(s):  
Kairui Cao ◽  
Guanglu Hao ◽  
Qingfeng Liu ◽  
Liying Tan ◽  
Jing Ma
Keyword(s):  
Neural Network ◽  
Back Propagation ◽  
Hysteresis Model ◽  
Cooperative Movement ◽  
Hysteresis Operator ◽  
The Neural Network ◽  
Hysteresis Nonlinearity ◽  
Hysteresis Modeling ◽  
Hysteresis Characteristics ◽  
Inverse Hysteresis

Fast steering mirrors (FSMs), driven by piezoelectric ceramics, are usually used as actuators for high-precision beam control. A FSM generally contains four ceramics that are distributed in a crisscross pattern. The cooperative movement of the two ceramics along one radial direction generates the deflection of the FSM in the same orientation. Unlike the hysteresis nonlinearity of a single piezoelectric ceramic, which is symmetric or asymmetric, the FSM exhibits complex hysteresis characteristics. In this paper, a systematic way of modeling the hysteresis nonlinearity of FSMs is proposed using a Madelung’s rules based symmetric hysteresis operator with a cascaded neural network. The hysteresis operator provides a basic hysteresis motion for the FSM. The neural network modifies the basic hysteresis motion to accurately describe the hysteresis nonlinearity of FSMs. The wiping-out and congruency properties of the proposed method are also analyzed. Moreover, the inverse hysteresis model is constructed to reduce the hysteresis nonlinearity of FSMs. The effectiveness of the presented model is validated by experimental results.

scholarly journals Theory of nonlinear magneto-optical imaging of magnetic domains and domain walls

1997 ◽  
Vol 56 (5) ◽  
pp. 2680-2687 ◽  
Author(s):  
A. V. Petukhov ◽  
I. L. Lyubchanskii ◽  
Th. Rasing
Keyword(s):  
Optical Imaging ◽  
Domain Walls ◽  
Magnetic Domains

scholarly journals Visualization of magnetostructural transition in Heusler alloys by Magnetic Force Microscopy

2018 ◽  
Vol 185 ◽  
pp. 05004
Author(s):  
Pavel Geydt ◽  
Igor D. Rodionov ◽  
Alexander B. Granovsky ◽  
Ekaterina Soboleva ◽  
Egor Fadeev ◽  
...  
Keyword(s):  
Magnetic Force Microscopy ◽  
Magnetic Force ◽  
Domain Walls ◽  
Heusler Alloys ◽  
Scanning Probe ◽  
Magnetic Domains ◽  
Magnetic Signal ◽  
Force Microscopy ◽  
Magnetostructural Transition ◽  
Probe Microscope

Magnetostructural transition was observed in Ni-Mn-In-Cr Heusler alloy with help of Magnetic Force Microscopy (MFM). The crystal structure of a sample and characteristic temperatures of the phase transition were controlled by roentgenostructural phase analysis and magnetometry, respectively. It appeared prominently important to prepare the surface of the sample until the nanometer level of surface roughness. Magnetic study performed with scanning probe microscope revealed existence of magnetic domains, which were spread across the surface evenly. Further studies revealed that intensity of magnetic signal decreases as fading out of the contrast of the MFM images. It was found that location of domains shifted after the heating/cooling cycle above Curie temperature for the studied alloy. Location of new domain walls appeared correlating with surface scrapings and defects, whilst it became independent from those after heating until just 70°C. The mechanism behind the observed transition is proposed.

scholarly journals In-Plane Magnetic Domains and Néel-like Domain Walls in Thin Flakes of the Room Temperature CrTe2 Van der Waals Ferromagnet

2020 ◽  
Vol 12 (27) ◽  
pp. 30702-30710 ◽  
Author(s):  
Anike Purbawati ◽  
Johann Coraux ◽  
Jan Vogel ◽  
Abdellali Hadj-Azzem ◽  
NianJheng Wu ◽  
...  
Keyword(s):  
Room Temperature ◽  
Domain Walls ◽  
Van Der Waals ◽  
Magnetic Domains

Behavior of Magnetic Domains in Single Magnetic Nanowire with Shallow Trench along Length Direction Observed by Magnetic Force Microscopy

2013 ◽  
Vol 1527 ◽  
Author(s):  
Mitsunobu Okuda ◽  
Yasuyoshi Miyamoto ◽  
Eiichi Miyashita ◽  
Naoto Hayashi
Keyword(s):  
Domain Walls ◽  
Hard Disk Drives ◽  
Magnetic Domain ◽  
Magnetic Memory ◽  
Magnetic Nanowires ◽  
Magnetic Domains ◽  
Electric Circuits ◽  
Recording Density ◽  
Magnetic Nanowire ◽  
Length Direction

ABSTRACTWe have proposed new magnetic memories using parallel-aligned nanowires without mechanical moving parts, in order to achieve the ultra high transfer rate of more than 144 Gbps for Super Hi-Vision TV. In the magnetic memory using nanowires, the data are stored as the magnetic domains with up or down magnetization in magnetic nanowires, and the domains are shifted quite faster by applying optimum current along the nanowire direction for data writing and reading purpose. Since the electric circuits and the insulation space between the neighbor nanowires are necessary for moving the magnetic domain walls, the areal recording density is essentially reduced as compared with that of conventional hard disk drives. In this study, in order to increase the areal recording density of magnetic nanowire memory, we have tried to act one magnetic nanowire as the virtual multiple data tracks. The shallow scratched trench was introduced using scanning probe microscopy along the length direction on the surface of a single nanowire to form multiple internal tracks, and we have succeeded in realizing a couple of virtual tracks states.

Magnetic Domains Observation from Bitter Patterns of NdFeB Alloy

2014 ◽  
Vol 802 ◽  
pp. 569-573 ◽  
Author(s):  
Raphael Lemos ◽  
Kaio Sérgio T. de Souza ◽  
Fernanda A. Sampaio da Silva ◽  
Daniel Rodrigues ◽  
José Adilson de Castro ◽  
...  
Keyword(s):  
Domain Walls ◽  
Cast Alloy ◽  
Colloid Solution ◽  
Magnetic Domains ◽  
Strong Anisotropy ◽  
Easy Magnetization ◽  
Domain Wall Energy ◽  
Magnetization Axis ◽  
Metallographic Preparation ◽  
Adequate Method

The Bitter method is an adequate method for domains observation, and depends on careful metallographic preparation and also on a proper magnetic colloid solution. In this study, Bitter patterns were obtained for a Nd-Fe-B as-cast alloy. The Nd2Fe14B grains show strong anisotropy during growing, and are larger for the direction perpendicular to the easy magnetization axis. The equilibrium distance between domain walls allows an estimate of intrinsic parameters of ferromagnetic phases as the domain wall energy and the single domain particle size.

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