Effect of sintering temperature on ferroelectric properties of 0.94(K 0.5Na 0.5)NbO 3–0.06LNbO 3 system

Abstract

Lead free 0.94(K 0.5Na 0.5NbO 3)–0.06(LiNbO 3) (KNN–LN) system was synthesized by conventional solid state reaction route (CSSRR). The KNN–LN system was calcined at 850 °C for 6 h for the formation of single perovskite phase whereas the sintering was done at 1050 °C, 1080 °C and 1100 °C for 4 h, respectively. The KNN–LN samples sintered at 1080 °C show better properties: room temperature (RT) dielectric constant ( ɛ r) ∼936, dielectric loss (tan δ) ∼0.016 at 1 MHz, a relatively high bulk density ( ρ) ∼4.385 g/cm 3, which is 97.5% of the theoretical density (TD ∼ 4.51), remnant polarization ( P r) ∼6.4 μC/cm 2 and coercive field ( E c) ∼9.6 kV/cm have been observed.