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1 Laboratoire de Physico-Chimie des Materiaux Luminescents, CNRS-UMR 5620, Universite Claude
Bernard Lyon I, 43 Bd du 11 novembre 1918, 69622 Villeurbanne Cedex, France
2 Laboratoire des Multimateriaux et Interfaces, CNRS-UMR 5615, Universite Claude Bernard Lyon I,
43 Bd du 11 novembre 1918, 69622 Villeurbanne Cedex, France
3 Laboratoire d'Electronique: Nanotechnologies, Capteurs, JE 2266 UCBL
Universite Claude Bernard Lyon I, 43 Bd du 11 novembre 1918, 69622 Villeurbanne Cedex, France
| Eu3+ doped HfO2 films are elaborated using sol-gel process. Crack-free thin films were obtained with excellent waveguiding properties. The nanostructural features of the layers depending on annealing temperature and doping concentration are investigated mainly by waveguide Raman spectroscopy in the very low frequency range and also by transmission electron microscopy. Two different solutions containing europium, with concentrations 0.1 at. % and 10 at. %, are prepared. The high doping content (10 at %) favours the crystallisation of the metastable tetragonal phase which lies in small nanograin size. This phase coexists with stable monoclinic phase for high doping content. The low doping content (0.1 at. %) crystallises into pure monoclinic phase at 500°C and the tetragonal phase appears at 750°C. The size of the nanograin affects the optical properties of the film. The refractive indices are higher for the 10 at % Eu3+ doped samples than for the 0.1 at % Eu3+ doped films. |
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