THE LIQUID-GLASS TRANSITION IN A STRONG NETWORK GLASS FORMER INVESTIGATED BY NEUTRON SCATTERING

The temperature dependence of the non-ergodicity parameter of a strong glass former, B2O3, has been investigated using neutron scattering. A clear change is observed at a temperature ( ~ 800 K) well above the glass-transition temperature ( ~ 523 K), and a complementary behaviour is observed for the strength of a fast relaxation process. The results directly shows the existence of a dynamic transition in the super-cooled melt of a strong network glass former. The transition, which is corroborated by the analysis of sound velocity and viscosity data, resembles that predicted by the mode coupling theory, and thereby shows the applicability of this theory even to strong glass formers.