SUPERIONIC CONDUCTIVITY IN THE AGI-AGVO3 SYSTEM

The AgIAgVO3 system was investigated by DSC, microthermal, X-ray diffractin and conductivity measurements. The phase transitions in solid samples obtained by quenching of the melt were reproducible and indicative of the formation of two types of transitions in solid samples obtained by quenching of the melt were reproducible and indicative of the formation of two types of glasses. In the composition range from 10 to 75 mol% AgI the liquidus curve was diffused. The system exhibited two eutectic temperatures at 275 and 360°C, respectively, which indicated that the basic components had reacted chemically forming a new compound. On the basis of estimates regarding the eutectic compositions it could be concluded that the new compound formed is AgI·2AgVO3. The polymeric nature of the latter is not excluded. The electrical conductivity of this system at room temperature depended on both the sample composition and the preparation procedure. The solid with 65 mol% AgI obtained by quenching of the melt was found to display a maximum conductivity of 2.2×10-2ω-1cm-1 at 294 K. By using the same preparation procedure, superionic conductivities were also obtained within a wider composition range, namely from 40 to 85 mol% AgI. © 1990.