Inelastic light scattering in superionic glasses ${\left(\mathrm{AgI}\right)}_x{\left({\mathrm{Ag}}_2\mathrm{O}·n{\mathrm{B}}_2{\mathrm{O}}_3\right)}_{1-x}$

Raman spectra in superionic glasses ${\left(\mathrm{AgI}\right)}_x{\left({\mathrm{Ag}}_2\mathrm{O}·n{\mathrm{B}}_2{\mathrm{O}}_3\right)}_{1-x}$ for various values of $x$ ($0.1\le x\le 0.55$) and for various $n \left(2\mathrm{}\le n\le 4\right)$ are reported. For comparison we also studied spectra of binary glasses (${\mathrm{Ag}}_2\mathrm{O}·n{\mathrm{B}}_2{\mathrm{O}}_3$). They provide light scattering experimental evidence of the network-modifier nature of the ${\mathrm{Ag}}_2$O in borate matrix. The model of Martin and Brenig for the interpretation of the low-frequency Raman band in the glasses is applied to the series of our samples with increasing content of AgI: A phenomenological "correlation length" is obtained from the study of the low-frequency peak of the various glasses, by introducing the values of the transverse and longitudinal sound velocities, obtained by ultrasonic measurements. That kind of calculation confirms our hypothesis of the increase on the correlation length from 8 Å at $x=0\mathrm{} \mathrm{to} 12$ Å at $x=0.55\mathrm{}$.