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材料科学技术学报 2007
Piezoelectric Properties of (Na0.5K0.5-xLix)NbO3 Ceramics
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Abstract:
Lead-free piezoelectric ceramics (Na0.5K0.5-xLix)NbO3 (x=0.057-0.066) were synthesized by an ordinary sintering technique. Substituting Li for K can lead to structural distortion, which improves the Curie temperature(TC) greatly. By adding appropriate LiNbO3 content, piezoelectric constant d33 values reach 202-212 pC/N.Electromechanical coefficients of the planar mode reach 44.4%-46.8%. The dielectric loss is below 2.6%,which is much lower than reported (about 50%). The TC of (Na0.5K0.5-xLix)NbO3 (x=0.057-0.066) is in the range of 490-510℃, at least 70℃ higher than that of pure (Na0.5K0.5)NbO3 ceramics. The results show that (Na0.5K0.5-xLix)NbO3 ceramic is a kind of good lead-free high-temperature piezoelectric material.