Topological Study of Densified Silica Glasses

Abstract

Silica glasses have anomalous behaviors on mechanical properties. Especially they show several complex deformation patterns upon compression. It is not clear how their structures are transformed without changing their coordination number. Structures of silica glasses upon compression are calculated using the molecular dynamics techniques. Then the calculated structures are analyzed in terms of coordination number, ring size and planarity index. The planarity index expresses the degree of planarity of Si-O rings. It is found that structural changes can be explained in terms of planarity index.