Chapter 1 Glass-formation in chalcogenide systems and periodic system

Abstract

Publisher Summary This chapter discusses the structural-energetic concept of glass-formation (with elements of kinetic approach) in chalcogenide systems. It is reported that the glass-formation in binary chalcogenide systems is mainly for chalcogenide-enriched compositions and determined by glass-forming types of phase diagrams characterized by low-temperature eutectics. The classification of ternary systems is proposed whose feature is the combination of types of phase diagrams of binary systems; a ternary system is glass-forming if between participating binary systems there is at least one system characterized by a glass-forming phase diagram. In accordance with the qualitative criterion of the glass-formation in ternary chalcogenide systems, glass-formation regions are usually located near lines of dilution of binary eutectics by the third component (element) of the common ternary system or/and near lines of dilution of binary eutectics by the chemical compound that is the component of a particular ternary system—the member of the common ternary system. In accordance with the quantitative criterion of glass-formation applied to chalcogenide systems with any number of components, the glass-formation ability of a substance is the ratio of the chemical, as a rule covalence—ionic, binding of one mole of atoms of this substance, and its liquidus temperature at the normal pressure. It is reported that in binary and ternary chalcogenide systems with elements of the third, fourth, fifth, and sixth groups of the periodic table. The common tendency of regular decrease in the glass-formation ability of alloys with increase in atomic numbers of elements in the group is manifested that correlates with increase in the metallization and decrease in the energy of chemical bonds.