**4. Conclusion**

The addition of ZnO nanoparticles with grain size of 59 nm has aided to successfully synthesize the BCZT/x ceramics at a relatively low sintering temperature of 1350°C. The added ZnO particles in nanoscale influenced the relaxor ferroelectric phase change of the materials. As a result, BCZT/0.15 composition possessed the highest diffuseness characteristic. Remanent polarization was improved and reached to a maximum value of 6.19 μC/cm2 at x = 0.15, whereas the coercive field went up continuously under increasing doping concentration. The ZnO addition has also improved the quality of the piezoelectric material, and best quality was observed for BCZT/0.15 composition, given that the values of d33, d31, kp, kt, and k33 are 420, −174, 0.483, 0.423, and 0.571 pC/N, respectively. The obtained results suggested that the lead-free BCZT/x material could be an expected lead-free piezoelectric ceramic for applications.

Besides, the influence of sintering temperature on structure, microstructure, and some piezoelectric parameters of BCZT/0.15 sample was examined. As the sintering temperature increased, improved sintering behavior and very high piezoelectric properties of d33 = 576 pC/N and kp = 0.55 were obtained for the sample sintered at 1450°C. As a comparison, corresponded properties of BCZT without ZnO nanoparticles or BCZT/0.00 specimen were investigated. The received results show that sintering behavior and some piezo-parameters of BCZT/0.15 samples are better than that of BCZT/0.00 samples at each sintering temperature. Especially, the difference in properties for samples sintered at 1450°C is attributed to competition between structure phases occurred in materials.

#### **Acknowledgements**

This work was carried out in the framework of the National Project in Physics Program until 2020 under no. ĐTĐLCN.10/18.

**153**

**Author details**

Dang Anh Tuan1

, Vo Thanh Tung2

2 University of Sciences, Hue University, Vietnam

provided the original work is properly cited.

\*Address all correspondence to: vttung@hueuni.edu.vn

\*, Le Tran Uyen Tu<sup>2</sup>

© 2019 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

1 Ha Nam Provincial Department of Science and Technology, Vietnam

and Truong Van Chuong2

*Synthesis and Investigation of the Physical Properties of Lead-Free BCZT Ceramics*

*DOI: http://dx.doi.org/10.5772/intechopen.87935*

*Synthesis and Investigation of the Physical Properties of Lead-Free BCZT Ceramics DOI: http://dx.doi.org/10.5772/intechopen.87935*
