Evidence for Phonon-Fracton Crossover in Silica Aerogels by Brillouin-Scattering Measurements

  • E. Courtens
  • J. Pelous
  • R. Vacher
  • T. Woignier
Part of the NATO ASI Series book series (volume 167)


Systems crossing over from homogeneity to self-similarity at a correlation length ξ are expected to exhibit rather peculiar elastic properties.1 Phonons of well-defined frequency ω and wavevector q can propagate in such media if their wavelength λ = 2π/q is larger than ξ. In contrast, a crossover to fractons, the vibrational excitations characteristic of fractal structures,2,3 should occur as qξ increases towards 1.


Elastic Scattering Fractal Structure Silica Aerogel Vibrational Excitation Scalar Elasticity 
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Copyright information

© Plenum Press, New York 1987

Authors and Affiliations

  • E. Courtens
    • 1
  • J. Pelous
    • 2
  • R. Vacher
    • 2
  • T. Woignier
    • 2
  1. 1.IBM Research DivisionZurich Research LaboratoryRüschlikonSwitzerland
  2. 2.Laboratoire de Science des Matériaux VitreuxUniversité des Sciences et Techniques du LanguedocMontpellierFrance

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