Some electroceramics, however, are very useful for the exact oposite reason - they can accomodate charge transfer. There are several methods of conducting in ceramic materials. The first is electronic conduction, similar to that of metals, and the second is ionic conduction, where charged atoms serve as carriers. This transfer is usually done via point defects called vacancies in the crystal lattice. Such movement can require high energy, making ionic conduction very strongly dependent on temperature.
Ionic conductors are useful in gas sensors, fuel cells, and batteries.
Materials that can accomodate electron conductivity as well as ionic conductivity are known as mixed conductors .