ABSTRACT
This chapter discusses structural relaxation processes in chalcogenide glasses in relation to the coordination of amorphous networks. The principle of mean coordination used to describe structural reticulation is irst presented, along with the theory of rigidity percolation. The concept of Angell’s fragility is reviewed, and the correlation between the mean coordination and the fragility of chalcogenide glass formers is discussed. The effect of fragility on the structural relaxation of chalcogenide glasses is then demonstrated for several relaxation processes, including thermally induced, photoinduced, and radiation-induced relaxation.
