Bismuth lead oxyfluroride ionic glass conductors

PosterMany works were published on anion conductors by ions O2 -, with good conductivities at 500-600°C. Oxyfluorides, conductors by ions F-, have the same level of performances around 300°C. For example, the oxyfluoride system containing bismuth and lead led to a crystallized phase having a conductivity of 1 Sm-1 at 300°C. Doping by silica makes it possible to stabilize a vitreous domain and extends the range of the conducting phases. The presented study relates to the stability of the vitreous phase and the variation of conductivity as well according to the temperature as versus the composition. Thermal analyses by DTA evidenced, after the temperature of vitreous transition, the recrystallization of material in one or more stages. The phases crystallized were identified by high temperature X-rays diffraction. The best conductivity, about 0,3 Sm-1 at 227°C, is obtained for the fluorine richest material