Electrical and optical characterization of Ag2V4O11 and Ag4V2O6F2

The two silver vanadium oxide phases-Ag2V4O11 and Ag4V2O6F2-were prepared by hydrothermal synthesis. The electrical conductivity of both silver vanadate powders was determined by the powder-solution-composite (PSC) method. The conductivities obtained were 0.0085 +/- 0.0005 and 0.0005 +/- 0.00015 S/cm for the Ag2V4O11 and Ag4V2O6F2, respectively, the first such report for the Ag4V2O6F2 phase. The optical gap and the transmission where studied by diffuse reflectance. Both were larger for Ag4V2O6F2 than Ag2V4O11, concomitant with a decrease in carrier content.