Micro Raman, FT-IR/PAS, XRD and SEM studies on glassy and partly crystalline silver phosphate ionic conductors

Glassy and glassy-crystalline silver ion conductors of the AgI–Ag2O–P2O5 system have been studied by FTIR-PAS and Micro Raman spectroscopies in conjunction with X-ray diffractometry, scanning electron microscopy and differential scanning calorimetry. It was found out that materials with lower (≤60 mol%) AgI contents are fully amorphous, while those with higher contents of AgI (>70 mol%) contain crystalline grains of β/γ-AgI embedded in the glassy matrix. Annealing of the glasses at 105 °C and/or 145 °C resulted in an increase in the formation of a yet unidentified crystalline phase dispersed in the glass. From the spectroscopic studies it was found that PO43− units existed as separated species in the glass network or precipitated crystalline phases regardless the thermal treatment of the material. Vibrations of PO43− units appeared to be affected by the total concentration of AgI and microstructure. The spectroscopic methods were also used to study crystallization process in the glassy samples.