Microstructure and electrical properties of potassium strontium niobate (KSr₂Nb₅O₁₅) ceramics

High-density tungsten bronze KSr₂Nb₅O₁₅ (KSN) ceramics doped with 2 mol% Bi2O3 were synthesized by using a conventional two-step sintering method with KSN seed. The effects of KSN seed content on microstructure and electric properties of the ceramics were investigated. It was found that the seed addition was favorable to the densification of KSN ceramics. The specimen with 25 mol% seed exhibited the best electric properties with values of D_t = 23.53%, P_r = 3.23 μC/cm² and d33 = 64 pC/N. In addition, pinched loops (ferroelectric hysteresis, P-E curve) were observed in the KSN ceramics, which may lead to novel application in nonlinear actuators. This work provided information on the interrelation between seed content and subsequent properties when preparing dense KSN textured ceramics by using (R)TGG method.