Size dependent grain-boundary conductivity in doped zirconia

The oxygen vacancy distributions at a grain boundary and resulting grain-bo undary 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-bounda ry conductivity with grain size is discussed. Compared with literature expe rimental results, the calculation results are reasonable. Finally, the feas ibility of Bauerle's equivalent electrical circuit for nanocrystalline mate rials is evaluated. (C) 2001 Elsevier Science B.V. All rights reserved.