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Elaboration par implantation ionique de nanoparticules de cobalt dans la silice et modifications de leurs propriétés sous irradiation d'électrons et d'ions de haute énergie

Abstract : This work aims to investigate the capability of ion irradiations to elaborate magnetic nanoparticles in silica layers, and to modify their properties. Co+ ions have been implanted at 160 keV at fluences of 2.1016, 5.1016 and 1017 at.cm-2, and at temperatures of 77, 295 and 873 K. The dependence of the particle size on the implantation fluence, and more significantly on the implantation temperature has been shown. TEM observations have shown a mean diameter varying from 1 nm for implantations at 2.1016 Co+.cm-2 at 77 K, to 9.7 nm at 1017 Co+.cm-2 at 873 K. For high temperature implantations, two regions of particles appear. Simulations based on a kinetic 3D lattice Monte Carlo method reproduce quantitatively the features observed for implantations. Thermal treatments induce the ripening of the particles. Electron irradiations at 873 K induce an important increase in mean particle sizes. Swift heavy ion irradiations also induce the ripening of the particles for low fluences, and an elongation of the particles in the incident beam direction for high fluences, resulting in a magnetic anisotropy. Mechanisms invoked in thermal spike model could also explain this anisotropic growth.
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https://tel.archives-ouvertes.fr/tel-00006290
Contributor : Céline d'Orleans <>
Submitted on : Monday, June 21, 2004 - 10:07:23 AM
Last modification on : Thursday, April 23, 2020 - 2:26:30 PM
Long-term archiving on: : Friday, April 2, 2010 - 8:55:17 PM

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  • HAL Id : tel-00006290, version 1

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Céline d'Orleans. Elaboration par implantation ionique de nanoparticules de cobalt dans la silice et modifications de leurs propriétés sous irradiation d'électrons et d'ions de haute énergie. Matière Condensée [cond-mat]. Université Louis Pasteur - Strasbourg I, 2003. Français. ⟨tel-00006290⟩

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