| mots-clés : épitaxie – dépôt laser pulsé – Couches tampon – Auto-organisation – Bandes – Anisotropie magnétique – Modélisation micromagnétique analytique – Renversement d'aimantation – Dichroïsme magnétique circulaire (XMCD) – Domaines magnétiques. |
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| Magnetic epitaxial films with tunable lattice parameter |
| The main aim of this thesis is to quantify the relation ship between misfit or a crystalline parameter different from the bulk one on one side and the behaviour of growth and magnetic properties on the other side. An original procedure, based on alternative pulsed laser depositions (PLD) from two different targets, has been developed to fabricate high quality buffer layers with a tunable lattice parameter and an independently controllable surface energy. This procedure is applied to the study of effects due to misfit and chemical interface on the growth and magnetic properties of thick selforganized iron stripes. Self-organized stripes of Fe were fabricated by PLD with a height up to five nanometers in contrast with results found in the literature (one or two atomic layers in height). This new elevated thickness allowed us to obtain remanence, coercivity, and/or splitting into stable magnetic domains at room temperature. Magnetic domains were revealed by X-ray circular magnetic dichroisme. Finally, we have proposed an analytical model of magnetization reversal in flat dots and stripes. This model predicts the values of both reversal and nucleation fields as function of the dot thickness. The results of this model are in good agreement with numerical simulations. |
| mots-clés en anglais : Epitaxy – Pulsed laser deposition – buffer layers – Self-organization – Stripes – Magnetic anisotropy – Analyticalmicro-magnetic modelling – Magnetization reversal – X-Ray Magnetic Circular Dichroism (XMCD) – Magnetic domains. |
