Concentration Dependences of Ionic Conductivity in Tysonite-like Solid Solutions

3 Concentration Dependences of Ionic Conductivity in Tysonite-like Solid Solutions 

It was assumed that, as with fluorites, the transfer model, taking into account clustering processes, percolations and charge carrier interactions, is suitable for Lai xSrxp3 x solid solutions (modification II) [115], 

When the doping concentration increases, the number of defect regions increases and, at a concentration called the percolation limit, Xper, the defect regions combine themselves into the joint conductivity channel. 

A maximum on concentration dependences of the conductivity at x 0,07 was observed for the tysonite-like Bij xBax(0,F)3 solid solution with the structure I (Rgure 14.39). The discoveiy of the ordered tysonite-like BiOyF3 2y phase (0.13 y 0.23) [34], with close composition, could serve as an indirect confirmation of the clustering mechanism described 

The influence of different doping types on the defect structure and conductivity of fluorine-containing phases with fluorite and tysonite structures has been discussed in the current review. The defect-region model including clustering and percolation phenomena has been used for describing the ionic transfer features in soUd solutions. 

---