HAL : in2p3-00129429, version 1
 arXiv : mtrl-th/9510003
 Molecular Dynamics Simulation of Electron Trapping in the Sapphire Lattice
 (1995)
 Energy storage and release in dielectric materials can be described on the basis of the charge trapping mechanism. Most phenomenological aspects have been recently rationalized in terms of the space charge model~\cite{blaise,blaise1}. Dynamical aspects are studied here by performing Molecular Dynamics simulations. We show that an excess electron introduced into the sapphire lattice (\alumina) can be trapped only at a limited number of sites. The energy gained by allowing the electron to localize in these sites is of the order of 4-5 eV, in good agreement with the results of the space charge model. Displacements of the neighboring ions due to the implanted charge are shown to be localized in a small region of about 5~Å. Detrapping is observed at 250 $K$. The ionic displacements turn out to play an important role in modifying the potential landscape by lowering, in a dynamical way, the barriers that cause localization at low temperature.
 Thème(s) : Physique/Matière Condensée/Science des matériaux
 Lien vers le texte intégral : http://fr.arXiv.org/abs/mtrl-th/9510003
 in2p3-00129429, version 1 http://hal.in2p3.fr/in2p3-00129429 oai:hal.in2p3.fr:in2p3-00129429 Contributeur : Dominique Girod <> Soumis le : Mercredi 7 Février 2007, 13:39:54 Dernière modification le : Mercredi 7 Février 2007, 13:56:42