Localized electrical characterization of the giant permittivity effect in CaCu3Ti4O12 ceramics

Nanoscale imaging of the electrical properties of CaCu3Ti4O12 ceramics has been performed using scanning impedance microscopy. Two kinds of electrical inhomogeneity are detected, namely, depletion layers at grain boundaries and calcium titanate inclusions, both of which are more resistive than the bulk of the grains. Energy filtered transmission electron microscopy was used to estimate the chemical composition of the inclusions. (c) 2008 American Institute of Physics.