Evidence of an Intermediate Phase in bulk alloy oxide glass sysem

Reversibility windows have been observed in modified oxides (alkali-silicates and -germanates) and identified with Intermediate Phases(IPs).\footnote{V. Rompicharla J. Phys.: Condens. Matter 20, 202101 (2008).} Here we find preliminary evidence of an IP in a ternary oxide glass, (B$_2$O3)$_5$(TeO$_2$)$_{95-x}$(V2O5)$_x$, which is composed of network formers. Bulk glasses are synthesized across the 18\% $<$ x $<$ 35\% composition range, and examined in Raman scattering, modulated DSC and molar volume experiments. Glass transition temperatures T$_g$(x) steadily decrease with V$_2$O$_5$ content x, and reveal the enthalpy of relaxation at T$_g$ to show a global minimum in the 24\% $<$ x $<$ 27\% range, the reversibility window (IP). Molar volumes reveal a minimum in this window. Raman scattering reveals a Boson mode, and at least six other vibrational bands in the 100 cm$^{-1}$ $<$ $\nu$ $<$ 1700 cm$^{-1}$ range. Compositional trends in vibrational mode strengths and frequency are established. These results will be presented in relation to glass structure evolution with vanadia content and the underlying elastic phases.