Department of Materials Science , Sichuan University , 610064 Chengdu , P. R. China.
Division of Physical Science and Engineering (PSE) , King Abdullah University of Science and Technology (KAUST) , Thuwal 23955-6900 , Saudi Arabia.
ACS Appl Mater Interfaces. 2018 Sep 12;10(36):30566-30573. doi: 10.1021/acsami.8b10136. Epub 2018 Aug 27.
Because of their high toxicity, lead-based materials in electronic devices must be replaced by lead-free piezoelectric materials. However, some issues remain that hinder the industrial applications of these alternative ceramics. Here, we report the construction of a 0-3-type ceramic composite (KNNS-BNKZ: xZnO), where the Sb-doped ZnO submicronic particles were randomly distributed throughout the potassium-sodium niobate-based ceramic matrix. In this (K,Na)NbO (KNN)-based ceramic composite, superior temperature stability, excellent piezoelectric properties, and a high Curie temperature were simultaneously achieved. The unipolar strain varied from +20 to -16% when the temperature was increased from 23 to 200 °C in KNNS-BNKZ: xZnO with x = 0.75. By increasing the ZnO content from x = 0 to x = 5.0, the Curie temperature was increased from 227 to 294 °C. More importantly, the piezoelectric coefficient remained high ( d = 480-510 pC/N) for a wide range of compositions, x = 0.25-1.0. Transmission electron microscopy (TEM) experiments showed that the compensatory electric fields generated by the Sb-doped ZnO submicronic particles were responsible for the improved temperature stability. The high piezoelectricity was due to the existence of nanodomains, which were clearly observed in the TEM experiments. The results presented in this work clarify some of the physical mechanisms in this KNN-based ceramic composite, thus advancing the development of lead-free ceramics.
由于其高毒性，电子设备中的含铅材料必须被无铅压电材料所取代。然而，一些问题仍然存在，阻碍了这些替代陶瓷的工业应用。在这里，我们报告了一种 0-3 型陶瓷复合材料（KNNS-BNKZ: xZnO）的构建，其中 Sb 掺杂 ZnO 亚微米颗粒随机分布在基于铌酸钾钠的陶瓷基体中。在这种基于（K，Na）NbO（KNN）的陶瓷复合材料中，同时实现了优越的温度稳定性、优异的压电性能和高居里温度。在 KNNS-BNKZ: xZnO（x = 0.75）中，当温度从 23°C 升高到 200°C 时，单极应变从+20%变化到-16%。通过将 ZnO 的含量从 x = 0 增加到 x = 5.0，居里温度从 227°C 升高到 294°C。更重要的是，压电系数在宽组成范围内（x = 0.25-1.0）保持较高（d = 480-510 pC/N）。透射电子显微镜（TEM）实验表明，Sb 掺杂 ZnO 亚微米颗粒产生的补偿电场是改善温度稳定性的原因。高压电性能归因于纳米畴的存在，这在 TEM 实验中清晰可见。本工作中的结果阐明了这种基于 KNN 的陶瓷复合材料中的一些物理机制，从而推进了无铅陶瓷的发展。
