The variation of the atomic density ϱ with the average coordination number Z for glasses belonging to the GexIn6Se94—x and GexIn12Se88—x families of the Ge–In–Se system is investigated. The ϱ— Z dependence displays broad maxima at Z values of 2.42 and 2.58 for families with 6 and 12 at% In, respectively. These maxima are ascribed to changes from a floppy to a rigid type network and from a two-dimensional layered structure to a three-dimensional network, respectively. The minima exhibited in the ϱ— Z dependence at Z = 2.63 for the In6 family and at Z = 2.71 for the In12 family, corresponding to the tie-line compositions, are attributed to chemical ordering effects.
physica status solidi (b) Volume 213, Issue 2, pages 261–265