Effect of Sr Dopant to the KNN-LiTaSb Properties

This research was investigating the effect of Sr concentration on the properties of KNN-LiTaSb samples in prepared on lead-free piezoelectric ceramic. The calcined powder of KNN samples were pressed at a pressure of 96 MPa using hand press to produce green body pallets followed by compacting using 300 MPa of CIP. Pelleted samples were placed in a close alumina crucible prior to sintering at 1130 degrees C for 2h in air atmosphere. The results show that dielectric properties (epsilon(r) and tan delta) were improved by the increment of Sr concentration. Increasing Sr concentration was transformed the crystal structure from initially orthorhombic symmetry for KNN sample to tetragonal symmetry as shown by XRD analysis. Addition of Sr also improved the density of KNN-LiTaSb body. This transition and densified body is responsible for the enhancement of dielectric properties with the optimum value obtained from sample doped at x= 0.01 mol% (epsilon(r) = 4000.57 and tan delta = 0.117). The most densified body identified at x= 0.01mol% of KNN-LiTaSb body (99.62%).