Andreas C. Cangellaris, Karen M. Coperich, et al.
EMC 2001
The density of vibrational states in a fractal silica aerogel of Hausdorff dimension D≃2.4 has been determined using spin-echo neutron spectroscopy. A smooth phonon-fracton crossover is found with a fracton spectral dimension of {Mathematical expression}. This direct measurement of {Mathematical expression} near crossover agrees with a previous finding based on scaling Brillouin-spectroscopy results obtained with several samples. We also show that protons adsorbed in the gel vibrate with substantially higher amplitude than the silica matrix. © 1990 Springer-Verlag.
Andreas C. Cangellaris, Karen M. Coperich, et al.
EMC 2001
Arvind Kumar, Jeffrey J. Welser, et al.
MRS Spring 2000
Biancun Xie, Madhavan Swaminathan, et al.
EMC 2011
J.K. Gimzewski, T.A. Jung, et al.
Surface Science