Numéro
J. Phys. IV France
Volume 135, October 2006
Page(s) 345 - 348
DOI http://dx.doi.org/10.1051/jp4:2006135114
Publié en ligne 23 novembre 2006
Neuvième colloque sur les lasers et l'optique quantique
C. Chardonnet et G. Millot
J. Phys. IV France 135 (2006) 345-348

DOI: 10.1051/jp4:2006135114

Second harmonic generation and Yb3+ cooperative emission as unusual ways to probe phase transitions in BaTiO3 sol-gel nanocrystals

J. Amami1, Y. Guyot1, C. Goutaudier1, G. Boulon1, M. Ayadi2, D. Hreniak3, R. Pazik3 and W. Strek3

1  Physical Chemistry of Luminescent Materials, UMR 5620 CNRS, Claude Bernard/Lyon 1 University, 69622 Villeurbanne, France
2  Physical Chemistry of Mineral Materials, Bizerte University, Tunisia
3  Institute of Low Temperature and Structure Research, Polish Academy of Sciences, Wroclaw, Poland
    e-mail: georges.boulon@pcml.univ-lyon1.fr


(Published online 23 November 2006)

Abstract
Nanocrystalline powders of 1% Yb3+-doped BaTiO3 sintered at different temperatures were obtained by the sol-gel method. The structure of the powders covering crystallite-sizes from 25 to 60 nm depending on the annealing temperature ( $700-1200^{\circ}$C) was determined from the Scherrer's equation. Second Harmonic Generation (SHG) intensity magnitude is compared in each samples of the tetragonal BaTiO3 whereas the isotropic cubic phase is detected by the absence of the SHG signal. Cooperative emission, indicating the Yb3+ ions pairs, was easily detected in the cubic phase and not seen in the ferroelectric tetragonal structure.



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