Etude de la croissance et des propriétés magnétiques de systèmes auto-organisés de nanofils de Fer(110)

Abstract : The present thesis is focused on the study of magnetic nanowires prepared by self-organized epitaxial growth. Two approaches were used: 1) Fabrication of a planar system of alternate nanostripes (Fe,Ag)/Mo(110). This growth mode is explained by the immiscible character of the two metals and by a modulated mechanism of epitaxial stress relaxation. 2) Preparation of Fe nanowires on a pre-patterned surface of periodic grooves. The grooves spontaneously form during the homoepitaxial growth of a bcc metal W(110) (or Mo) at moderate temperature. The unidimensional patterning with hills and grooves shows a tunable period through the deposition temperature. In a second step iron is deposited at a specific temperature on this template and grows from the bottom of the grooves, to form regularly spaced wires. A tridimensionnal network was also prepared by vertically stacking the planar wires array.Magnetically, the two systems show a strong anisotropy with the easy axis of magnetization in-plane along the wires. At room temperature both systems are superparamagnetic. The temperature dependence of the coercivity is explained within a thermally activated magnetization reversal process through nucleation/propagation. The reversal involves several coupled wires for the first system, but takes place in the individual wires for the second one.
Document type :
Theses
Physics [physics]. Université Joseph-Fourier - Grenoble I, 2007. French


https://tel.archives-ouvertes.fr/tel-00130572
Contributor : Bogdana Borca <>
Submitted on : Monday, February 12, 2007 - 5:09:43 PM
Last modification on : Friday, March 16, 2007 - 1:59:34 PM

Identifiers

  • HAL Id : tel-00130572, version 1

Collections

UJF | NEEL | UGA

Citation

Bogdana Borca. Etude de la croissance et des propriétés magnétiques de systèmes auto-organisés de nanofils de Fer(110). Physics [physics]. Université Joseph-Fourier - Grenoble I, 2007. French. <tel-00130572>

Export

Share

Metrics

Consultation de
la notice

94

Téléchargement du document

141