Dielectric, ferroelectric and piezoelectric properties of (1−x)[K0.5Na0.5NbO3]−x[LiSbO3] ceramics
Lead-free (1−x)[K0.5Na0.5NbO3]−x[LiSbO3] (x=0, 0.04, 0.05 and 0.06)/(KNN-LS) ceramics were prepared by conventional solid-state reaction route (CSSR). For dense morphology pure KNN ceramic was sintered at 1120 °C and LS modified KNN ceramics were sintered at 1080 °C for 4 h, respectively. The structural study at room temperature (RT) revealed the transformation of pure orthorhombic to tetragonal structure with the increase in LS content in KNN-LS ceramics. Temperature dependent dielectric study confirmed the increase of diffuse phase transition nature with the increase in LS content in KNN-LS ceramics. The presence of orthorhombic to tetragonal (TO−T) polymorphic phase transition temperature (PPT) ∼43 °C confirmed the presence of two ferroelectric (orthorhombic and tetragonal) phases in 0.95KNN-0.05LS ceramics at RT. 0.95KNN-0.05LS ceramics showed better ferroelectric and piezoelectric properties i.e., remnant polarization (Pr)∼18.7 Î¼C/cm2, coercive field (Ec)∼11.8 kV/cm, piezoelectric coefficient (d33)∼215 pC/N, coupling coefficient (kp)∼0.415 and remnant strain ∼0.07% were obtained. âº Effect of LiSbO3 content on the electrical properties of KNN ceramics within the MPB region. âº Optimization of poling temperature to obtain better piezoelectric properties. âº Increase of diffuse phase transition nature with the increase in LiSbO3 content. âº Temperature dependence of piezoelectric properties have been studied.