Stéphane Labbé


Professeur de l'Université Joseph Fourier, Grenoble

HM-MAG : Hytérésis et Modélisation des micro-objets MAGnétiques

Essential

Magnetic micro ob jects take an important place in domains such as nano- electronic, magnetic recording or characterization. The aim of the study is to model the behavior of the magnetization in small magnetic ob jects in order optimize their performances in complex systems. In this study we will focus on two main themes: the development of a mesoscopic model from the atomistic description of the material and the understanding of the hysteresis which is a strong characterization tool. The micro-scale modeling has two main aims: to understand the Landau-Lifchitz equation of the micromagnetism theory and particularly the dissipation coe?- cient and to introduce the heat inßuence in the dynamic micromagnetic model. In the hysteresis part of the pro ject, we are interested in demonstrating the exis- tence of hysteresis and characterizing the cycle, for the dynamic micromagnetic model. The main challenges are the understanding of the Barkhausen noise phenomenon, in particular we would like to investigate if this phenomena is at least partially modeled by the micromagnetism theory.

International position

The transition between atomic and mesoscopic scales has not been studied math- ematically yet, but physicist are very interested in understanding the real link between the micromagnetic model and the ab-initio model of magnetic materi- als. This understanding is of great importance in building a mesoscopic model for nano-electronic purpose, in particular, in taking into account the caloriÞc phenomenon. Nowadays, many physical laboratories are developing research programs on this subject. Hysteresis has been mathematically studied, for example, by A. Visintin for simpliÞed magnetic systems using additional contribution in order to obtain the hysteresis behavior forecasted by physicists. In the physical point of view, hysteresis is particularly useful in order to study ferromagnetic materials and try to characterize the presence of defects in the crystalline structure.

Financement

Le projet HM-MAG est financé par le RTRA Nano-sciences de Grenoble.

Les personnes investies dans le projet

Labbé Stéphane (Enseignant-chercheur, responsable),
Bidegaray Brigitte (Chercheur, collaborateur),
Dumas Eric (Enseignant-chercheur, collaborateur),
Bokoch Serguiy (Post-doctorant fondation Nano-Sciences, collaborateur),
Jouet Quentin (Doctorant UJF, collaborateur),

Les publications

Nouvelles