Author(s)

Chaouki Bensalem, Michel Mortier, Daniel Vivien, Patrick Gredin, Gilles Patriarche, Madjid Diaf

Département de Physique, Université d’Annaba, Annaba, Algérie.
Laboratoire de Chimie de la Matière Condensée de Paris, UPMC, Chimie ParisTech, Paris, France.
Laboratoire de Photonique et Nanostructures, Marcoussis, France.

The devitrification of glasses with composition 50GeO₂-40PbO-10PbF₂-xREF₃, RE = Gd, Eu, 0 < x ≤ 2, leads to glass ceramics made of RE³⁺: β-PbF₂ nanocrystals embedded in a glassy oxide matrix. This transformation is investigated using thermal analysis, X-ray diffraction and electron microscopy. A comparison with RE³⁺: β-PbF₂ ceramics prepared by standard ceramic techniques is performed. The Rare Earth cations show a strong nucleating effect for the precipitation of the RE³⁺+: β-PbF₂ nanocrystals. The evolution of the unit cell parameters of the REF3: β-PbF₂ solid solution results from a combined effect of Pb²⁺-RE³⁺ substitution and interstitial F– introduction. In the glass ceramics, RE³⁺: β-PbF₂ nanocrystals are constrained by the glassy matrix when they form with a pressure equivalent to 1.6 GPa. The constrained nanocrystals can return to a relaxed state by chemical dissolution of the embedding glassy matrix, followed by thermal treatments.

Glass-Ceramic; Rare-Earth; Thermal Analysis; Devitrification; Nanocrystallite; X-Ray Diffraction

C. Bensalem, M. Mortier, D. Vivien, P. Gredin, G. Patriarche and M. Diaf, "Thermal and Structural Characterization of Transparent Rare-Earth Doped Lead Fluoride Glass-Ceramics," New Journal of Glass and Ceramics, Vol. 2 No. 2, 2012, pp. 65-74. doi: 10.4236/njgc.2012.22010.