Lead-free ceramics (1-x)(Na0.5K0.5)NbO3-xBi(Sc0.5Fe0.5)O-3 (KNN-BSF, x = 0-0.08) were synthesized by conventional solid-state sintering. A morphotropic phase boundary (MPB) is formed in the ceramics near x = 0.01-0.02 at room temperature by X-ray analysis. Dielectric temperature spectra indicate the existence of two dielectric anomalous peal's, which correspond to orthorhombic-tetragonal (T-OT) and tetragonal-cubic (T-C) transitions. The cerarnic with x = 0.0125 near the MPB exhibits the following optinial electrical properties: P-r = 33.9 mu C/cm(2), E-c = 18.1 kV/cm, d(33) = 255 pC/N, k(p) = 0.44, and T-c = 372 degrees C.

Keywords: Piezoelectric materials; Electrical Properties; Ferroelectrics; Ceramics