CHEMICAL-BOND APPROACH TO THE CHALCOGENIDE GLASS FORMING TENDENCY

The nature of chemical bonds of some chalcogenide glasses is discussed in terms of the chemical bond approach. It was found that there is a correlation between the chalcogenide glass forming ability and the number of lone-pair electrons for a chalcogenide or chalcogenide system. The stable vitreous state can be obtained only if enough lone-pair electrons exist in the structure of the chalcogenide system. The cation in the chalcogenide glasses may interact with the lone-pair electrons of a bridging chalcogen atom and influence the glass forming ability. A simple criterion for computing the ability of a chalcogenide system to retain its vitreous state is proposed. Experimental results support the above analysis.