Dc-electrical degradation of the BT-based material for multilayer ceramic capacitor with Ni internal electrode: Impedance analysis and microstructure

The impedance of a BaTiO3 (BT)-based multilayer ceramic capacitor with a ni ckel internal electrode (Ni-MLCC) was investigated by measuring the frequen cy domain at various temperatures. All the obtained impedance data could be successfully fitted to a 4-RC section electrical equivalent network. The 4 -RC section electrical equivalent network was successfully correlated to th e microstructure: the core, the shell, the grain boundary, and the ceramic/ internal electrode interface regions. Based on this electrical equivalent n etwork, the electrical properties including the Curie-Weiss law, the curren t-voltage characteristics, and dc electrical degradation, were well explain ed. A model for the degradation behavior for BT-based Ni-MLCC with thin act ive layer thickness was proposed.