Résumé
The structural relaxation of viscous (Na2O-Li2O)-2P(2)O(5) is investigated by neutron spin-echo experiments. The spectra show stretching and time-temperature scaling as known from a-relaxation in supercooled liquids and derived from mode-coupling theory (MCT). The momentum transfer dependence of the correlation times is found to exhibit a maximum value at the first maximum of the structure factor S(Q) in agreement with predictions of MCT. In contrast, the Q-dependence of the stretching exponent beta does not seem to oscillate in phase with S(Q) in this network glass. (C) 2004 Elsevier B. V. All rights reserved.