An interstitialcy theory of structural relaxation and related viscous flow of glasses.
A theory of isothermal structural relaxation and creep of glasses below the glass transition temperature is given. According to the interstitialcy theory, the supercooled liquid state does not exist below a Kauzmann "pseudocritical" temperature T(k), which lies above the temperature T(K), commonly called the "Kauzmann temperature." Structural relaxation is simply a reduction with time of the interstitialcy concentration to the crystalline state for T<T(k), and to the metastable supercooled liquid state for T>T(k). The predicted viscosity eta is universal, given by eta=eta(0) + eta(T)t, in agreement with experiment. eta is continuous in T, with eta discontinuous at T(k) but linear in 1/T above and below T(k). The dependence of eta on the shear modulus directly connects kinetic and thermodynamic properties of glasses and liquids.
Granato
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Department of Physics, University of Illinois at Urbana-Champaign, 1110 West Greet St., Urbana, Illinois 61801, USA.
Khonik
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