Microstructure and impedance analysis of CaBi4Ti4O15 piezoceramics with (LiCe)-modifications

(Li, Ce) doped CaBi₄Ti₄O₁₅ (CBT) ceramics were prepared using the conventional solid state method. The crystal structure and microstructure of CBT-based ceramics were determined by the X-ray diffraction and scanning electron microscopy. It was found that the (Li, Ce) ions diffused into the A site of pseudo-perovskite structure and formed single Aurivillius type structure. The Curie-temperature (T_C) of CBT ceramics decreased whereas the piezoelectric coefficient (d₃₃) was improved with the increasing of (Li, Ce) dopants. Furthermore, the impedance spectrum techniques were invoked to understand the electrical properties for pure or modified-CBT compounds at high temperature region and the underlying physical mechanism were also discussed.