Abstract
The electric potential distribution within a commercial multilayer ceramic capacitor under an applied voltage was determined by electron holography. We demonstrated that equipotential contour lines present essential information about the electrical conductivity of submicrometer-scale precipitates formed in commercial BaTiO3 multilayer ceramic capacitors. Considerable changes observed in the equipotential contour map of precipitates could be explained by simulations taking into account the electrical conductivities of the precipitates and BaTiO3 matrix. This method can lead to a deeper understanding of the relationship between the complex microstructure and the material functionalities in capacitors widely used in industry.
Fig. 1 (a) Schematic illustration of a thin-foil specimen of a multilayer ceramic capacitor. Refer to the text for details. (b) ADF-STEM image of a thin-foil specimen. The yellow patches indicate deposited Pt electrodes to forming part of the anode. The black arrows in the middle indicate the position of precipitate. (c) Nonlinear I–V curve obtained from local resistivity measurement of the thin-foil specimen.
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