Structure and Properties of (K0.5Na0.5)1-2xSrx(Nb0.94 Sb0.06)O3 Lead-free Piezoelectric Ceramics

Leada2free piezoelectric ceramics (K0.5Na0.5)1-2xSrx(Nb0.94 Sb0.06)O3 (abbreviated as KNSNS1000x) were synthesized by the conventional ceramic sintering technique. The structure and electrical properties of KNSNS1000x ceramics were investigated. The results of XRD indicate that KNSNS1000x ceramics have an orthorhombic structure. The proper content of Sr substitute increases the density of ceramics which reaches the maximum value of 4.411g/cm3 at x=0.008. With the increase of the amount of Sr, the Tc decreases and the temperature of orthorhombica2tetragonal phase transition (To-t) is almost a constant.In the temperature range from 0 o 200 dielectric constant of KNSNS1000x ceramics is independent of frequency. The KNSNS8 ceramics obtains the optimum piezoelectric properties: d33=155pC/N, kp=0.361￡ Qm=120￡ Np=2862￡ Pr=23| /cm2￡ Ec=1.4kV/mm￡ | /EM>=4.411g/cm3.