BiFeO3-modified (Li, K, Na)(Nb, Ta)O3 lead-free piezoelectric ceramics with temperature-stable piezoelectric property and enhanced mechanical strength
BiFeO3-modified (Li, K, Na)(Nb, Ta)O3 lead-free piezoelectric ceramics with temperature-stable piezoelectric property and enhanced mechanical strength
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DOI：
10.1007/s10853-011-5957-y
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发表时间：
2012-02
影响因子：
4.5
通讯作者：
Jia-Jun Zhou;Jingfeng Li;Xiaowen Zhang
中科院分区：
文献类型：
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作者：
Jia-Jun Zhou;Jingfeng Li;Xiaowen Zhang
采用常规方法制备了BiFeO_3修饰的无铅压电陶瓷Li0.05(Na0.515K0.485)0.95Nb0.8Ta0.203(LKNNT)，研究了其对相结构、电学性能和力学性能的影响。微量的BiFeO_3(BF)使LKNNT的相结构由四方转变为伪立方体，并有效地改善了LKNNT的烧结性能和致密化，从而提高了LKNNT的力学性能。添加1%BF的LKNNT压电陶瓷的体积密度为5.02g/cm3，断裂强度提高到142g/cm3，高于放电等离子烧结法制备的同类样品，其室温电性能为d33~225ppm/V，Kp~36.3%，εr~1140，Tgδ~0.018，Tc~305℃，Qm~80。在LKNNT50-150℃的温度范围内，介电性能的变化率在−50-150℃的温度范围内保持不变，这可以归因于LKNNT型压电陶瓷的相结构与温度无关，这使得该陶瓷成为一种有希望的实际应用候选材料。
BiFeO3-modified lead-free piezoceramics Li0.05(Na0.515K0.485)0.95Nb0.8Ta0.2O3(LKNNT) were successfully fabricated by conventional method to investigate its influences on phase structure and electricity as well as mechanical properties. A tiny amount of BiFeO3(BF) changes the phase structure of LKNNT to tetragonal and further to pseudocubic, and also effectively improves the sintering ability and densification of LKNNT which enhances the mechanical property. The LKNNT piezoceramics with the addition of 1 mol% BF has the bulk density of 5.02 g/cm3and an enhanced fracture strength of 142 MPa which is even higher than that of the sample of similar composition prepared by spark plasma sintering, also possesses room temperature electric properties ofd33* ~ 225 pm/V,kp~ 36.3%,εr~ 1140, tgδ ~ 0.018,Tc~ 305 °C andQm~ 80. Thed33* remains constant up to 150 °C and the change ratio of dielectric property largely decreases over the temperature range of −50–150 °C, which can be attributed to the temperature-independent phase structure of LKNNT piezoceramics, making the ceramics as a promising candidate for actual applications.