系统研究(1-y)[(Na0.80K0.16Li0.04)0.5Bi0.5]TiO3-yBa(Zr0.055Ti0.945)O3无铅压电陶瓷,获得压电应变常数高达185pC/N的0.94[(Na0.80K0.16Li0.04)0.5Bi0.5]-TiO3-0.06Ba(Zr0.055Ti0.945)O3压电陶瓷。样品的晶体结构为三方相、四方相共存,处于准同型相界(morphotropic phase boundary,MPB)附近。该类陶瓷室温MPB的摩尔(下同)含量为0.050〈y〈0.065。样品y=0.060在40°左右的(003)、(021)双峰与46.5°左右的(002)、(200)双峰分裂最明显。随着Ba(Zr0.055Ti0.945)O3含量的增加,铁电相-反铁电相相变温度(θd)升高、反铁电相-顺电相相变温度(θm)降低;θd和θm的温差越来越小,材料的弛豫性逐渐降低。
Lead-free piezoelectric ceramics(1-y)(Na0.80K0.16Li0.04) 0.5Bi0.5TiO3-yBa(Zr0.055Ti0.945) O3 were systematically investigated. The 0.94(Na0.80K0.16Li0.04) 0.5Bi0.5TiO3-0.06Ba(Zr0.055Ti0.945) O3 ceramics with a piezoelectric strain constant as high as 185 pC/N was obtained.The structure of the sample can be seen in the results,with the morphotropic phase boundary(MPB) of the ceramics lying in the composition mole content(the same below) of 0.050y0.065 at room temperature,where rhombohedral and tetragonal phases coexist.The(003) /(021) peak splitting around 42°and the(002) /(200) peak splitting around 46.5°of the samples are more obvious.The phase transition temperature(θd) from rhombohedral ferroelectric to tetragonal anti-ferroelectric increases as Ba(Zr0.055Ti0.945) O3 content increases.Accordingly,the phase transition temperature(θm) from tetragonal anti-ferroelectric to tetrago-nal paraelectric decreases.The relaxation feature of the material decreases with the difference betweenθd andθm becoming less and less.