STRUCTURE-PROPERTY INTERRELATIONS IN CHALCOGENIDE GLASSES AND THEIR PRACTICAL IMPLICATIONS

To understand the effects of structural features and to locate their s ignatures in the glassy and the liquid states, various properties were studied as a function of average coordination number, [r], in chalcog enide glasses and examined in relation to the chemically ordered coval ent network model and constraint theory. The former predicts a thresho ld at [r] = 2.67 and the latter a threshold at [r] = 2.4. It is noted that most of the properties exhibit a threshold at [r] = 2.67 while on ly some show the threshold at [r] = 2.4. The reasons for the existence of the thresholds and various practical applications based on composi tion-property relationships are discussed. (C) 1997 Elsevier Science B .V.