Electrical properties of CaBi4Ti4O15–Bi4Ti3O12 piezoelectric ceramics

CaBi4Ti4O15–Bi4Ti3O12 (CBT–BIT) ceramics were synthesized using a solid state reaction method. The X-ray diffraction (XRD) analysis revealed the existence of bismuth layered perovskite phase with orthorhombic crystal structure. High-resolution transmission electron microscopy (HRTEM) confirmed the alternate arrangement of CBT part and BIT part along c axis in the intergrowth structure. CBT–BIT ceramics showed excellent thermal stability of the dielectric loss (tan δ), but the relaxation of dielectric loss in the 100 Hz to 1 MHz frequency range had been observed. Meanwhile, an enhanced piezoelectric constant (d33) value of 15 pC/N was observed without degradation even the temperature up to 650 °C. The dc resistivity (ρdc) of CBT–BIT performed a high value of 5.68×1014 (Ω cm) at room temperature (RT). In addition, the ρdc values of CBT–BIT within the temperature range of 100–450 °C were close to those of CBT and kept almost one hundred times higher than those of BIT.