Abstract:
Formation of highly ionically conducting and thermally stable amorphous phase during mechanical ball milling of AgI–Ag2O–V2O5 system is discussed. It is found that the system with composition xAgI(100−x)–66.66Ag2O–33.34V2O5 for x=50, 60 and 67 forms a highly conducting amorphous phase within 10–15 h of mechanical milling, confirmed by X-ray diffraction, glass (Tg) and amorphous to crystalline phase transition (Tc) temperatures. The ionic conductivity of mechanochemically synthesized samples is found to be ∼10−2 cm−1 at room temperature, which is appreciably higher than that of the melt-quenched glass. These systems are found to be stable at least up to ∼80 °C as confirmed by differential scanning calorimetry measurements. A tentative mechanism of amorphous phase formation is proposed. It is demonstrated that silver iodide that diffuses in Ag2O–MxOy matrix plays a key role in the formation of amorphous phase.