Scaling Nonlinear Elasticity in Silica Aerogels

Brillouin scattering measurements have been performed on a series of fractal silica aerogels under applied uniaxial pressure. The entire nonlinear elastic behaviour scales with the aerogel density using the single scaling exponent that characterizes linear elasticity. Further, the anomalous nonlinear elasticity of the aerogels extrapolate to that of fused silica, strongly suggesting a common origin.