| Domaine : |
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| Titre : |
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Optical evidence of energy level crossing and anticrossing for U4+ diluted in the incommensurate structure of β-ThCl4 |
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| Auteur(s) : |
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Anita Milicic-Tang1, Pierre Delamoye1, Jean-Claude Krupa1 |
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| Laboratoire : |
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| Résumé : |
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At low temperatures β-ThCl4 undergoes a structural phase transition (Tc=70 K) to an incommensurate structure which can be described as a transverse sinusoidal displacement of the chloride ion positions in a plane perpendicular to the C4 axis of the crystal. These static, atomic displacements induce a continuous distribution of crystal field strengths acting on U4+ embedded in the host matrix. The peculiar lineshapes recorded on absorption spectra and the apparently continuous character of fluorescence energies observed in selective excitation experiments are consistent with a continuous distribution of U4+ sites. In this paper we report a study of the interactions of Stark energy levels belonging to the 1I6 multiplet of U4+ (in the 19 700-19 500 cm-1 energy range) in a magnetic field. Absorption and selectively excited emission spectra recorded at 4.2 K have been used to build an energy level model. The calculated profile of the absorption bands in a magnetic field B parallel to the 〈111 〉 orientation is compared to the experimental observed ones. |
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Langue du texte
intégral : |
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Anglais |
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Date de production,
écriture : |
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1991 |
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| Journal : |
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| Journal de Physique I (J. Phys. I) |
| Publisher |
EDP Sciences |
| ISSN |
1155-4304 (eISSN : 1286-4862) |
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| Audience : |
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non spécifiée |
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| Type de publication : |
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Articles dans des revues avec comité de lecture |
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| Date de publication : |
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1991 |
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| Volume : |
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1 |
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| Numéro : |
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6 |
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| Page, identifiant, ... : |
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917-930 |
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