Size dependent grain-boundary conductivity in doped zirconia

The oxygen vacancy distributions at a grain boundary and resulting grain-boundary conductivities were calculated as a function of grain size, with an emphasis on nanocrystalline materials. The cause for the “intrinsic” grain-boundary blocking effect is analyzed, and the variation of the grain-boundary conductivity with grain size is discussed. Compared with literature experimental results, the calculation results are reasonable. Finally, the feasibility of Bauerleʹs equivalent electrical circuit for nanocrystalline materials is evaluated.