No abstract

The Group 16 elements are frequently named as chalcogens ('ore builders'). From the geographical point of view, they are known as chalcophiles which are the soft elements (keeping in mind the terminology of the hard/soft acids and bases concept). In the geographical sense, chalcophiles preferably form minerals with sulfur (S), selenium (Se) and tellurium (Te). However, oxygen (O) tends to bind preferably to lithophiles, which are hard elements such as the alkali metals, early transition metals, and silicon. The special position of oxygen amongst the chalcogen elements is its association with its very high electronegativity, which in turn correlates with its high ionization energy and the small atomic radius; which makes it difficult for oxygen to act as a central atom in electron-rich multicentre bonds. In the present script, we have reviewed the models for theoretical prediction of some significant physical parameters i.e. coordination number, constraints, density, molar volume, cohesive energy and heat of atomization etc. for the three generations of Se rich multicomponent glasses are presented. The present theoretical study of the multi-component chalcogenide glasses reveals that there is a significant change in the structural environment of the three generations (binary, ternary and quaternary systems) due to rigidity percolation.

The value of N increases with the rise in LP as a signature of metal-induced effects of Cd, In and Sb.

According to recent literature, germanium-containing chalcogenide glasses (ChGs) show improvement in thermal stability and glass-forming ability because of the self-organization of the glass network towards a more rigid structure.