Structural relaxation and self-organization in network glasses at stiffness transition

Abstract We have investigated the changes in quasi-elastic (QE) relaxation behavior in a low-frequency range 10–80 cm −1 near stiffness transition in Ge x Se 1− x glasses using temperature-programmed Raman scattering technique. We confirm that the QE contribution originates from the fast (β) process of relaxation. Since the QE intensity depends on glass composition, the origin of the relaxational modes is traced to floppy modes. We attribute the relaxation modes mainly to the damping or jumping motions of the rotating Se n segments, which could be regarded as the microscopic origin of floppy modes in the Se-contained network glasses.