Articles collected on (around) 2000.03.22 on the topic of magnetic hysteresis simulation.
No. Records Request * 1 9 "simulation of hysteresis" Record 1 of 5 - CC Search(R) 7 Editions Part 3
Metal evaporated tape (MET) has a complex column-like structure in which magnetic domains are arranged randomly. In order to accurately simulate the behaviour of MET it is important to capture these aspects of the material in a high-resolution 3-D micromagnetic model. The scale of this problem prohibits the use of traditional scalar computers and leads us to develop algorithms for a vector processor architecture. We demonstrate that despite the materials highly non-uniform structure, it is possible to develop fast vector algorithms for the computation of the magnetostatic interaction field. We do this by splitting the field calculation into near and far components. The near held component is calculated exactly using an efficient vector algorithm, whereas the far field is calculated approximately using a novel fast Fourier transform ( FFT) technique. Results are presented which demonstrate that, in practice, the algorithms require sub-O(N log(N)) computation time. In addition results of highly realistic simulation of hysteresis in MET are presented.
Since the first laws discovered by Lord Rayleigh in 1887, the literature has given a spectacular number of works in the magnetisation modeling field. The authors remark that most of these works are devoted to soft magnetic metals with intent to improve the knowledge of the dynamic power losses (anomalous losses), and that only a few models have really been developed on true physical considerations. In the soft ferrites area, Globus has proposed a model of magnetisation based on the motions (reversible bulgings and irreversible movements of translation) of a single 180 degrees domain wall contained in an ideal spherical grain. The authors discuss the main assumptions of this model with regard to their own practical experience of soft ferrites (actions of external anisotropies), and also to some particular results published by other workers. In the last part of this paper, a new progress on the Globus model is presented which concerns the hysteresis simulation. The result is tested on actual hysteresis loops of different shapes.
A simulation algorithm is proposed which reproduces, at a great CPU time saving, solutions of multilevel master equations used to describe thermally driven dynamics of interacting: particle arrays. Hysteresis loops for planar particle arrays are computed and the stability of intermediate, partially demagnetized configurations and their dependence on array size are discussed.
This article describes the advances in unification of model descriptions of hysteresis in magnetic materials and demonstrates the equivalence of two widely accepted models, the Preisach (PM) and Jiles-Atherton (JA) models. Recently it was shown that starting from general energy relations, the JA equation for a loop branch can be derived from PM. The unified approach is here applied to the interpretation of magnetization measured in nonoriented Si-Fe steels with variable grain size [s], and also in as-cast and annealed Fe amorphous alloys. In the case of NO Fe-Si, the modeling parameter k defined by the volume density of pinning centers is such that k approximate to A+B/[s], where the parameters A and B are related to magnetocrystalline anisotropy and grain texture. The value of k in the amorphous alloys can be used to estimate the microstructural correlation length playing the role of effective grain size in these materials. (C) 1999 American Institute of Physics. [S0021-8979(99)23808- X].
By means of Monte Carlo simulation the hysteresis of non-intereacting single-domain magnetic particles presenting cubic crystalline anisotropy are studied. Both signs of the anisotropy constant are considered and relevant properties, such as remanence and coercivity, are obtained as a function of temperature. (C) 1999 Elsevier Science B.V. All rights reserved.