Influence of SrBi2Nb2O9 (SBN) incorporation in K0.5Na0.5NbO3 (KNN) ceramics on its structural and electrical properties

This paper presents the study of electrical and ferroelectric behaviour of lead-free solid-solution with the end members belonging to two distinct families: perovskite and bismuth layer-structured ferroelectrics (BLSF). (1-x) (K_0.5Na_0.5NbO₃) - x (SrBi₂Nb₂O₉) (x = 0.10, 0.20, 0.30, 0.40, and 0.50 mol %) ceramics were prepared using solid-state reaction. XRD and Raman spectroscopy were used to study the phase formation. A dense and irregular grain distribution was observed from SEM images. Addition of SBN in KNN tends to lower the transition temperature (from 379 °C to 372 °C), ε_r (from 435 to 375) and P_r (from 9.49 μC/cm² to 2.85 μC/cm²) initially up to x = 0.30, however T_c and P_r increase with further increase in SBN composition. The composition with x = 0.5 shows enhanced ferroelectric properties with ε_r = 473, T_c = 417 °C, P_r = 13.81 μC/cm² and E_c = 31.96 kV/cm which makes this ceramic composition a potential candidate for ferroelectric capacitor and memory devices.