Simultaneous enhancement of piezoelectricity and temperature stability in Pb(Ni <sub>1/3</sub>Nb <sub>2/3</sub>)O <sub>3</sub>–PbZrO <sub>3</sub>–PbTiO <sub>3</sub> piezoelectric ceramics via Sm-modification
Kai Li, Shan Cong, Lang Bian, Zhenting Zhao, Jie Wu, Junfeng Zhao, Duoduo Zhang, Haijuan Mei, Sun Enwei, Xudong Qi, Weiping Gong, Bin Yang
Abstract
The development of piezoelectric ceramics characterized by both large piezoelectric response and high temperature stability is imperative for the advancement of practical electromechanical devices. However, existing high-performance piezoelectric ceramics often encounter compromised temperature stability due to ferroelectric phase transitions occurring within low-temperature regions. In this work, we focused on Sm-doped Pb(Ni<sub>1/3</sub>Nb<sub>2/3</sub>)O<sub>3</sub>-PbZrO<sub>3</sub>-PbTiO<sub>3 </sub>(PNN-PZT:Sm) ceramics with tetragonal (T)-phase structure to achieve the desired combination of large piezoelectricity and high temperature stability. The results indicate that 2 mol% Sm-doped samples exhibit a large piezoelectric constant <em>d</em><sub>33</sub> of 575 pC/N, an effective piezoelectric strain coefficient <em>d</em><sub>33</sub><sup>*</sup> of 890 pm/V, and a high <em>T</em><sub>m</sub> of 279 °C. Remarkably, the <em>d</em><sub>33</sub> experiences only a 2.6% variation over the temperature range of 30 °C to 250 °C, while the <em>d</em><sub>33</sub><sup>*</sup> changes by 8% within the temperature range of 30 °C to 180 °C. Microstructural and domain structure analyses suggest that Sm-doing effectively reduces the grain size, leading to decreased domain size, thereby achieving excellent electromechanical properties. The superior temperature stability is attributed to the suppressive effect of Sm-doping on the R-T ferroelectric phase transition. These studies suggest that Sm-doping represents an effective strategy for achieving the collaborative optimization of piezoelectricity and temperature stability through grain and domain engineering techniques for perovskite ferroelectric materials.