Anomalous temperature dependence of the first diffraction peak in vitreous boron trioxide.

The temperature dependence of the parameters characterizing the first peak in the S(Q) and S(Q ,E50) diffraction patterns of vitreous boron trioxide is considered in some detail. The analysis of the experimental spectra is aided by results derived from molecular-dynamics simulations, which enable us to isolate the most relevant features driving the variation with temperature of both structure factors. The relevance of the present results regarding some recent phenomenological approaches developed towards the understanding of the dynamics of glasses at intermediate temperatures is finally discussed. @S0163-1829~96!00325-6#