Dielectric and Structural Properties of Layer‐Structured Sr1−xCaxBi2Nb2O9

Sr 1− x Ca x Bi 2 Nb 2 O 9 ( x =0, 0.2, 0.4, 0.6, 0.8 and 1) ceramics were prepared by a conventional solid‐state reaction method. Their dielectric and structural properties were investigated. X‐ray diffraction analysis indicated that single‐phase layered perovskites were obtained. For Ca‐substituted specimens, a dielectric relaxation peak is observed in the temperature range of 30°–150°C, and there is a broader para‐ferroelectric phase transition peak. The temperature of the maximum dielectric constant T m increases linearly with increasing Ca content. Raman spectra indicate that a small amount of Ca 2+ is incorporated into Bi sites in the Bi 2 O 2 layers, and an increase in the degree of distortion of NbO 6 octahedra for Ca‐substituted specimens should be one of the reasons for the increase in T m compared with SrBi 2 Nb 2 O 9 .