| It is well known that lead zirconate titanate (PZT)-based ceramics showed excellent piezoelectric properties. However, the facts that lead oxide vaporizes during processing and that it causes harm to the environment lead to the legislations in many countries. In view of the above, it is necessary to try to find alternatives or replacements for the conventional lead-based materials and several environmentally friendly lead-free systems have been suggested. In this paper, sodium potassium niobate-based ceramies were selected as the experimental system, (Ko.44Nao.5oLio.o6)(Nb1_xSbx)03 were prepared by the conventional mixed oxide route. Microstructures were studied according x-ray diffraction,scanning electron microscope etc.Dielectric,piezoelectric, properties were measured by d33 meter, impedance analyzer etc.The effect of Sb5+ substituting content on the piezoelectric,dielectric and electromechanical properties of sodium potassium niobate lead free piezoelectric ceramics was also studied and its result provided the foundation for the further experiments. The effects of sintering temperature on the density, structure and electric properties of (K0.44Nao.5oLio.o6)(Nbo.97Sbo.o3)03 ceramics were also studied. The results show that when Sb5+ substituting content is 0.03 and sintering temperature is 1080℃, good comprehensive properties can be obtained:p=4.32g/cm3,εr=795, tanδ=0.043, d33=204pC/N, kp=0.34。Lastly, SrTiO3 modified (Ko.44Nao.5oLio.o6)(Nbo.97Sbo.o3)03 system were studied. The influence of SrTiO3 content on the phase structure, microstructure, dielectric and piezoelectric properties of the ceramics was investigated in detail. The XRD analysis results showed that all the ceramics were rhombohedral phase. With the increasing of SrTiO3 content, d33, kp and tanδdecreased, whereas the mechanical quality factor Qm increased singinificantly after the addition of SrTiO3, which showed the SrTiO3 acting as "hard dopant" in the (Ko.44Nao.5oLio.06)(Nbo.97Sbo.o3)03 system.
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