Antiferroelectric-like properties and enhanced polarization of Cu-doped K0.5Na0.5NbO3 piezoelectric ceramics
Antiferroelectric-like properties and enhanced polarization of Cu-doped K0.5Na0.5NbO3 piezoelectric ceramics
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DOI：
10.1063/1.4747212
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发表时间：
2012-08
影响因子：
4
通讯作者：
Shanming Ke;Haitao Huang;H. Fan;H. Lee;Limin Zhou;Y. Mai
中科院分区：
文献类型：
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作者：
Shanming Ke;Haitao Huang;H. Fan;H. Lee;Limin Zhou;Y. Mai
在铜掺杂 K0.5Na0.5NbO3 (KNN) 陶瓷中观察到铁电磁滞 (P-E) 回线的异常演变。 1 摩尔。 % Cu 掺杂的新鲜样品表现出双环特征，而 1.5 和 2 mol。 % Cu 掺杂 KNN 陶瓷显示出正常的单环。电子顺磁共振谱证实了这些陶瓷中不可转换的 (CuNb‴−VO••) ′ (DC1) 和非极性 (VO••−CuNb‴−VO••)• (DC2) 缺陷复合物的形成。根据实验结果，表明DC1将提供域反向切换的驱动力，导致双P-E环，而DC2将有助于空间电荷。样品的介电老化行为也支持了这一机制。正是 DC1 和 DC2 缺陷复合物之间的竞争导致了在 Cu 掺杂 KNN 陶瓷中观察到的 P-E 环的成分演化。
Abnormal evolution of ferroelectric hysteresis (P-E) loops was observed in Cu-doped K0.5Na0.5NbO3 (KNN) ceramics. The 1 mol. % Cu-doped fresh sample exhibited double-loop-like characteristics, while the 1.5 and 2 mol. % Cu-doped KNN ceramics showed normal single loops. Electron paramagnetic resonance spectra verified the formation of non-switchable (CuNb‴−VO••) ′ (DC1) and non-polar (VO••−CuNb‴−VO••)• (DC2) defect complexes in these ceramics. According to the experimental results, it is suggested that DC1 would provide the driving force for domain back-switching, leading to the double P-E loops, while DC2 would contribute to the space charges. Dielectric aging behaviors of the samples also supported this mechanism. It is the competition between the DC1 and DC2 defect complexes that induced the observed compositional evolution of P-E loops in the Cu-doped KNN ceramics.