预烧温度对(Ba0.85Ca0.15)(Ti0.9Hf0.1)O3压电陶瓷电性能的影响

采用固相法分别在1100~1250 ℃的预烧温度下制备了(Ba0.85Ca0.15)(Ti0.9Hf0.1)O3(BCHT)无铅压电陶瓷,通过对所制备陶微观结构和电性能的测试,发现:所有样品均具有纯的钙钛矿结构;随预烧温度的增加,室温下样品逐渐由四方相向三方相转变,预烧温度在1150~1250 ℃时两相共存;样品的压电常数d33、剩余极化强度Pr均随预烧温度的升高呈现先减小后增加的趋势,相对介电常数εr、弥散系数γ呈现先增加后减小的趋势,而矫顽场Ec则逐渐降低.样品的综合性能在预烧温度1250 ℃处达到最佳值: d33=525 pC/N,Pr=10.2 μC/cm2,Ec=1.30 kV/cm,εr=17699,γ=1.65,表明该材料具有良好的应用前景.

Effect of Calcining Temperature on Piezoelectric Properties of (Ba0.85Ca0.15)(Ti0.9Hf0.1)O3 Lead-Free Piezoelectric Ceramics

(Ba0.85Ca0.15)(Ti0.9Hf0.1)O3 (abbreviated as BCHT)lead-free piezoelectric ceramics were prepared successfully using a solid state reaction method.The effects of calcining temperature (1100~1250 ℃) on the microstructure and electrical properties of the BCHT ceramics were investigated.The results indicate that all the samples possess a pure perovskite phase structure.The phase structure of the sample change from tetragonal phase to rhombohedral phase around room temperature with increased calcining temperature, and the rhombohedral phase and tetragonal phase coexist in the composition range of 1150~1250 ℃.Meanwhile, the piezoelectric constant d33, remnant polarization Pr first decrease and then increase,and dielectric constant εr , diffusion coefficient γ first increase and then decrease,the coercive field Ec decreased with increasing the amount of calcining temperature.The comprehensive properties of (Ba0.85Ca0.15)(Ti0.9Hf0.1)O3 exhibits optimum value at 1250 ℃: d33=525 pC/N, Pr=10.2 μC /cm2, Ec=1.30 kV/cm, and εr =17699, γ=1.65, which indicates that the ceramic has a good application prospect.