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Fluid Dynamics Seminar

Monday, Oct. 22, 2012, 4:00 PM
Cullimore, Room 611
New Jersey Institute of Technology

Survey of Micromagnetic Modelling Techniques

Gabriel Chaves

Department of Mathematical Sciences, New Jersey Institute of Technology

Abstract

Magnetic materials have become ubiquitous in electromechanical devices. The understanding of the dynamics of the magnetization field is required at a wide range of scales: from the behavior of transformers and motors at the macroscale, to the behavior of magnetic particles as small as ~1000 atoms useful for information storage. Micromagnetics deals with this problems by treating fields in a continuous limit with a classical description of the magnetization vector. The biggest challenge arise from the multiscale nature of the problem. The finest details result from a strong exchange interaction and determines the biggest permissible spatial discretization. At the same, the magnetostatic interaction is weak but long range. The need to accurately account for both limits makes micromagnetic a field of research were new techniques are constantly developed. This talk will start with the physical theory of micromagnetism. And will discuss the different approaches to calculate the various energy terms. Among these there are finite difference, finite element, multipole expansions and reduced problem methods. The dynamics of the magnetization will be introduced. And a brief description of thermal effects and its critical role on the reliability of memory devices will be discussed. Recent work on annular structures will be presented.