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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)

Abstract

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.

Keywords

Elastic Scattering Fractal Structure Silica Aerogel Vibrational Excitation Scalar Elasticity 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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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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