The conductivity relaxation of glasses in this system, with NaF contents ranging from 5 to 30mol%, were studied at frequencies ranging from 10Hz to 2MHz and temperatures ranging from 300K to just below the glass transition temperature (table 215). The conductivity decreased with increasing NaF content, and this was shown to result from an increasingly lower decoupling of F- ions from the viscous motion of the glassy network. Low values of the stretching exponent were observed, and were attributed to a high degree of cooperation between F- ions in the conductivity relaxation process.

M.Sural, A.Ghosh: Journal of Physics - Condensed Matter, 1999, 11[16], 3315-22

Table 215

Ionic Conduction Parameters for ZrF4-BaF2-YF3-NaF Glasses