采用固相法制备了(Na0.5Bi0.5)TiO3+xmol%Y2O3+xmol%Fe2O3(0≤x≤1.25)(简称NBTYF)无铅压电陶瓷。XRD衍射结果表明,所有陶瓷样品均为单一的钙钛矿结构。SEM表明,掺杂后陶瓷的晶粒尺寸增大。介电温谱表明该体系陶瓷具有弛豫特性,随掺杂量的增加,退极化温度Td向低温方向移动,而居里温度Tc向高温方向移动。陶瓷的密度和压电常数d33和随x的增加先增大后减小,而机械品质因子Qm一直下降。当x=1.00时,该体系陶瓷具有最佳压电性能,d33=106pC/N,Qm=93,kp=16.08%,εr=594,tanδ=5.33%,ρ=5.699g/cm3。
The(Na0.5Bi0.5)TiO3+xmol%Y2O3+xmol%Fe2O3(0≤x≤1.25)(abbreviated as NBTYF) lead-free piezoelectric ceramics were fabricated by solid state reaction.X-ray diffraction results reveal that the sintered NBTYF ceramics exhibit a pure perovskite structure.SEM observation suggests that the grain size of those materials increases as the Y2O3 and Fe2O3 content increasing.Temperature dependence of dielectric constant shows that this system ceramics have relaxor characteristics.Furthermore,the depolarization temperature(Td) shifted to low temperature direction and the Curie temperature(Tc) moved to the high temperature direction with increasing Fe3+ and Y3+ concentration.The density of the ceramics and piezoelectric constant d33 increase first and then decrease while mechanical quality factor Qm decreases with the increase of Y2O3 and Fe2O3 content.This system ceramics with the best comprehensive properties can be obtained at x=1.00,d33,Qm,kp,εr,tanδ and ρ is 106 pC/N,93,16.08%,594,5.33% and 5.699g/cm3,respectively.