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Local structure around Er3+ in SiO2-HfO2 glass and nanocrystalline waveguides with

Francesco Rocca
2009
2009
Istituto di fotonica e nanotecnologie - IFN
XAFS14 - XIX “International Conference on X-ray Absorption fine Structure” , 26-31 July 2009
No
Camerino, MC (Italia)
Abstract: Er3+-doped SiO2 glass has been the basic material for fabricating photonics and optoelectronics devices. Introducing oxide glasses into the basic hosting material may enhance the solubility of the rare earth ion in the host glass and alter the crystalfield around these ions. Recently, this procedure has been extended to growing nanocrystalline phases of the co-dopant oxide, where the rare earth ions may substitute the cations. In the past, we reported on Er3+-doped SiO2 planar waveguides having HfO2 content between 10 and 50 mol %. In the present study we are interested in the changes of the local environment of Er3+ samples with low HfO2 (less than 10 mol %). Planar waveguides with the compositions 1 mol % Er3+-doped (1-x)SiO2-xHfO2 (x=0.0, 0.9, 1.8, 5, and 8 mol %) were prepared by sol-gel route and deposited on amorphous SiO2 substrates using dip-coating technique. All the samples were densified at 900 oC for 72 h. Replicates of the glasses with 5 and 8 % were successively heat treated at 1100 oC for 30 min to grow HfO2 nanocrystals. The local structure around Er3+ ions in all samples was characterized by fluorescence Er L3-edges EXAFS measurements at BM08 GILDA Beamline of ESRF. In the glassy waveguides, EXAFS data show the presence of Er3+ ions in HfO2-rich regions for HfO2 concentrations over 5 mol %. It is found that the local structure around the rare earth ions is dependent on HfO2 content. This information complements the previous one on high HfO2 contents, where the local structure around Er3+ ions remains unaltered for HfO2 concentrations between 10 and 50 mol %. In the nanocrystalline samples, even at 5 mol % HfO2, it was possible to grow HfO2 nanocrystals. For these samples, EXAFS data suggest the substitution of Hf by Er ions in the present nanocrystals.
6
none
Diab Afify, Nasser; Dalba, Giuseppe; Grisenti, Rolly; Sanson, Andrea; Armellini, Cristina; Rocca, Francesco
273
info:eu-repo/semantics/conferenceObject
04 Contributo in convegno::04.01 Contributo in Atti di convegno
04.01 Contributo in Atti di convegno
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/20.500.14243/80014
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