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Communication Dans Un Congrès Année : 2007

Z-Invariant Micromagnetic Configurations in Cylindrical Domains

Stéphane Labbé

Résumé

In this presentation, we have proposed a rather complete study of the micromagnetic model when the configurations are assumed to be vertically invariant, the (fixed) domain is cylindrical and when the exchange constant vanishes to 0. The result is given as a Γ− convergence theorem and when the external magnetic field has a small enough magnitude, it fully explains the Van den Berg construction. Moreover, the hypothesis of a small exterior field enables us to catch the (form of) the next order term in energy. This term is achieved with a kind of Bloch walls instead of Néel walls for thin films. From a physical point of view, it is known that typical walls in thick films are the so-called "assymetric Bloch walls'' which consist in a Bloch wall inside the thickness of the sample closed by Néel caps on the top and bottom parts of wall. Thus, our results may seem physically meaningless. On the other hand, the numerical computations given in show that in thick films, the magnetization is vertically invariant in the core part of the wall and the top and bottom Néel caps are small in thickness. Hence, our model could well explain the core part of the (asymetric) Bloch wall, the Néel parts being caught energetically by the fact that our configurations are not tangent to the (horizontal) boundaries on the top and bottom parts. Indeed, if most of the configuration is vertically invariant, our ansatzes become relevant.
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Dates et versions

hal-00750553 , version 1 (10-11-2012)

Identifiants

  • HAL Id : hal-00750553 , version 1

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Stéphane Labbé. Z-Invariant Micromagnetic Configurations in Cylindrical Domains. SIAM Conference on Analysis of Partial Differential Equations, Dec 2007, Mesa, Arizona, United States. ⟨hal-00750553⟩
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