Piezoelectric and ferroelectric properties of [Bi0.5(Na1−x−yKxLiy)0.5]TiO3 lead-free piezoelectric ceramics
Piezoelectric and ferroelectric properties of [Bi0.5(Na1−x−yKxLiy)0.5]TiO3 lead-free piezoelectric ceramics
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DOI：
10.1063/1.2171799
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发表时间：
2006-02
影响因子：
4
通讯作者：
Dunmin Lin;D. Xiao;Jianguo Zhu;P. Yu
中科院分区：
文献类型：
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作者：
Dunmin Lin;D. Xiao;Jianguo Zhu;P. Yu
采用混合氧化物法制备了Bi0.5(Na1-x-yKxAgy)0.5TiO3[BNKAT(x/y)]无铅压电陶瓷。考察了K+、Ag+含量对电学性能的影响。X-射线衍射图表明，在烧结过程中，K+和Ag+离子部分取代了Bi0.5Na0.5TiO3中的Na+离子，形成了固溶体。在室温下，陶瓷具有良好的性能，其压电常数d33=189pC/N，机电耦合系数Kp=35.0%，剩余极化Pr=39.5μC/cm~2，矫顽场Ec=3.3kV/mm。介电常数Er和损耗正切tanδ随温度的变化曲线表明，随着K+含量的增加，铁电相向反铁电相的转变温度降低。Kp和极化-电滞回线对温度的依赖关系表明，BNkat(0.15/0.015)陶瓷的退极化温度Td在160℃以上，该陶瓷在室温下具有良好的压电性能(D33=134pC/N，Kp=32.5%)和较强的铁电性(Pr=39.5kV/μC/cm~2，EC=4.1kV/mm)。
Lead-free piezoelectric ceramics Bi0.5(Na1-x-yKxAgy)0.5TiO3 [BNKAT(x/y)] have been synthesized by the mixed oxide method. The effects of the amount of K+ and Ag+ on the electrical properties were examined. X-ray diffraction patterns indicate that K+ and Ag+ ions partially substitute for the Na+ ions in Bi0.5Na0.5TiO3 and form a solid solution during sintering. At room temperature, the ceramics exhibit good performances with piezoelectric constant d33=189 pC/N, electromechanical coupling factor kp=35.0%, remanent polarization Pr=39.5 μC/cm2, and coercive field Ec=3.3 kV/mm, respectively. The curves of the dielectric constant er and loss tangent tan δ versus temperature show that the transition temperature from ferroelectric to anti-ferroelectric phase decreases with increasing the K+ content for the compositions researched. The dependencies of kp and polarization versus electric (P–E) hysteresis loops on temperature reveal that the depolarization temperature Td of BNKAT(0.15/0.015) ceramics, which have good piezoelectric properties (d33=134 pC/N, kp=32.5%) and strong ferroelectricity (Pr=39.5 μC/cm2, Ec=4.1 kV/mm) at room temperature, is above 160 °C.