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Spectral Shape of Relaxations in Silica Glass

Johannes Wiedersich·Sergei V. Adichtchev·Ernst R"ossler
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Abstract

Precise low-frequency light scattering experiments on silica glass are presented, covering a broad temperature and frequency range (9 GHz < ν< 2 THz). For the first time the spectral shape of relaxations is observed over more than one decade in frequency. The spectra show a power-law low-frequency wing of the relaxational part of the spectrum with an exponent $α$ proportional to temperature in the range 30 K < T < 200 K. A comparison of our results with those from acoustic attenuation experiments performed at different frequencies shows that this power-law behaviour rather well describes relaxations in silica over 9 orders of magnitude in frequency. These findings can be explained by a model of thermally activated transitions in double well potentials.

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Johannes Wiedersich, Sergei V. Adichtchev, Ernst R"ossler. 1999-12-16. Spectral Shape of Relaxations in Silica Glass. https://doi.org/10.1103/physrevlett.84.2718

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