Raman scattering, microstructural and dielectric studies on Ba1−xCaxBi4Ti4O15 ceramics

► Ba1−xCaxBi4Ti4O15 (0 ≤ x ≤ 1) ceramics with four-layer Aurivillius structure were fabricated. ► X-ray diffraction and Raman scattering techniques have been employed to probe into the structural changes on changing x. ► Curie temperature (TC) was found to increase with increase in Ca-doping whereas the diffuseness of phase transition decreased. ► Temperature coefficient of dielectric constant can be tuned over a wide range of temperature by changing Ca-content. ► Ferroelectric and piezoelectric properties are investigated.