Fine structure, mechanical characteristics and mid-range order in xZnO-yNa2O-(1-x-y)SiO2 glasses

The differentiation between the behavior of Zn2 + and Na + cations in silicate network is shaded by the lack of characteristic infrared or Raman bands belonging to the modes involving the zinc- or sodium-oxygen bonds. It was shown in this study that the stepwise substitution of Na2O for ZnO in the xZnO-yNa2O-(1-x-y)SiO2 glasses with keeping approximately the same SiO2 content causes the high-frequency shift of the Raman-active boson peak (BP) that is the decrease of the correlation length in structural glass heterogeneities. Intercomparison of this trend with variations of the measured structural strength and microhardness of the glasses under consideration afforded ground to suggestion of a possible dual role of Zn2 + ion as either glass-modifier or glass former in specific compositions of zinc-alkali-silicate glasses.