A direct method to solve quasistatic micromagnetic problems
| Autor: | E. Blaabjerg Poulsen, Rasmus Bjørk, Kaspar Kirstein Nielsen, Andrea Roberto Insinga |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
010302 applied physics
Equilibrium point Physics Field (physics) Differential equation 02 engineering and technology Decoupling (cosmology) 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences Electronic Optical and Magnetic Materials Magnetic field Hysteresis 0103 physical sciences Relaxation (physics) Statistical physics 0210 nano-technology Quasistatic process |
| Zdroj: | Insinga, A R, Blaabjerg Poulsen, E, Nielsen, K K & Bjørk, R 2020, ' A direct method to solve quasistatic micromagnetic problems ', Journal of Magnetism and Magnetic Materials, vol. 510, 166900 . https://doi.org/10.1016/j.jmmm.2020.166900 |
| ISSN: | 0304-8853 |
| DOI: | 10.1016/j.jmmm.2020.166900 |
| Popis: | Micromagnetic simulations are employed for predicting the behavior of magnetic materials from their microscopic properties. In this paper we focus on hysteresis loops, which are computed by assuming quasistatic conditions: i.e. the magnetization distribution remains at equilibrium while the applied magnetic field is slowly varied.The dynamic behavior of micromagnetic systems is governed by the Landau-Lifshitz equation. In order to apply the dynamic equation to a quasistatic problem, it is necessary to artificially decouple the relaxation dynamics from the time-scale of the variation of the applied field. This decoupling is normally done in an iterative fashion: the field is considered fixed until the equilibrium point is reached, and subsequently updated. However, this approach is indirect and also has the potential issue that a system might switch to a different equilibrium configuration before the previous equilibrium becomes unstable, which is a behavior not possible in the quasistatic regime.Instead, here we derive the differential equation, which directly describes the evolution of the equilibrium states of the Landau-Lifshitz equation as a function of the external field, or any other externally varied parameter. This approach is a more rigorous description of quasistatic processes and inherently enforces the system to follow a given equilibrium configuration until this disappears or becomes unstable. We demonstrate this approach with simple examples and show it to be as or more stable than the previously used approaches. |
| Databáze: | OpenAIRE |
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