Electrical conduction properties of Sr-doped Bi4(SiO4)3 with the eulytite-type structure

Electrical conduction in 1 mol% Sr-doped Bi4(SiO4)3 with the eulytite-type structure at elevated temperatures was investigated with conductivity measurements. Conductivity of the material under wet condition was higher than that under dry condition, and were 1.2  ×  10−6 – 9.7  ×  10−5 S cm−1 at 500–850 °C. From H/D isotope effects and p(O2)-dependencies of the conductivity, it was found that the Sr-doped Bi4(SiO4)3 exhibited protonic conduction at all the temperatures investigated while contribution of p-type conduction became significant with increasing p(O2) and/or temperature. Protonic and p-type conductions in the material were discussed in terms of defect equilibria.