Dielectric, Piezoelectric, Pyroelectric Properties and Polymorphic Phase Transition of 0.95 (K<sub>X</sub>Na<sub>1-X</sub>) NbO<sub>3</sub>-0.05LiSbO<sub>3</sub> Lead-Free Ferroelectric Ceramics

Abstract

0.95 (KXNa1-X) NbO3-0.05 LiSbO3(KNN-LS-X) (X=0.4-0.5) lead-free ceramics were prepared by conventional solid method. The effect of K/Na ratio on the dielectric, piezoelectric, pyroelectric and polymorphic phase transition was studied. The results show that the electrical properties strongly depend on the K/Na ratio. The KNN-LS-X(X=0.45) ceramics exhibit enhanced properties (εr=891.267,d33=222pC/N,Kp=0.43517,Qm=64.72,p=15×10-4C/m2K). Enhanced electrical properties of the KNN-LS-X (X=0.45) ceramics could be attributed to the effect of K/Na ratio modifying the polymorphic orthorhombic-tetragonal phase transition temperature to room temperature, which could make KNN-LS-X (X=0.45) ceramics use as a new ferroelectric sensor.