What are the effects of frenkel and schottky defects on electrical conductivity of a solid?

How do these two defects impact dielectric constant of solid? Please explain these two questions in detail.
In case of frenkel defect the the smaller ions are just dislocated from their initial positions. In that case the electrical conductivity must remain unaltered. But I have found out from few sources that electrical conductivity decreases due to increase in resistance so I am a bit confused.


