Grain boundary segregation in oxide ceramics

The factors which control grain boundary segregation in oxide ceramics are reviewed. These include grain boundary energy, cation–cation interactions, impurity cation size, as well as electrostatic interactions with the grain boundary space charge. In addition, an approach for measuring grain boundary segregation in those materials, as a function of the five macroscopic parameters of grain boundary character, is described. This experimental method relies on the coupled application of orientation imaging microscopy and scanning Auger spectroscopy.