Laboratoire Charles Coulomb UMR 5221 CNRS/UM2 (L2C)


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Origin of hypersonic sound wave attenuation in silica and porous silica (vycor, xérogels)

par Sébastien LAYSSAC - publié le

Evidence of a relaxation peak at low temperature due to impurities ; evidence of a geometric scattering contribution by disorder at the nanometer scale. Competition between anharmonicity and relaxations for the origin of hypersonic sound wave attenuation in glasses.

Publications :
C. Levelut and J. Pelous ,J. Phys. Cond. Matt., 19 (2007) 416110
J. Pelous and C.Levelut Phys. Rev. B, 72, issue 22, 224202 (2006).
C. Levelut, R. Le Parc, and J. Pelous, Phys. Rev. B 73 052202 (2006)

- Collaborations with ICGM
V. Ranieri’s Ph. D work at ICGM on crystal growth of(SiO2)x(GeO2)(1-x) compounds with quartz structure, in order to look for new piezoelectric materials

Publications :
V. Ranieri et al, Physical Review B 79 224304 (2009)
R. Le Parc et al Journal of Applied Physics 103 (2008) 094917.

- Phase transitions in nanostructured PZT ceramic.
Better fundamental understanding of multiferroic materials (ferroelectric materials with magnetic ordering).
Collaboration J. Rouquette, J. Haines, G. Fraysse, A . AL Zein (ICGM)

- Phase transitions and pressure behavior in GaxAl1-xPO4 solid solutions with quartz structure.
Influence of chemical disorder on the amorphization process.

Publications :
J. Haines, O Cambon, R. Le Parc and C. Levelut, Phase transitions 80 (2007) 1039-1049
E. Angot et al : J. Phys. : Cond. Matt., 188, 4315 (2006).