The Effect of Excess Sodium Element on KNN-BF Piezoelectric Ceramics

Abstract:

Lead-free (K0.5Na0.5)0.992Nb0.992-0.008BF-xNa (KNN-BF-xNa) piezoelectric ceramics with excess Na doping were synthesized using the sol-gel method at the sintering temperature of 1100°C. The effects of excess Na-doping on microstructure and properties of the lead-free piezoelectric ceramics were systematically investigated with x from 0.00 to 0.04. As x increased into 0.03, the acutest peak of x-ray diffraction patterns appeared; the SEM fig.1(c) showed regular and dense crystal shape. KNN-BF-0.03Na ceramics showed excellent properties of d33=149pC/N, εr=641(f=1KHz), tanδ=0.06(f=1KHz), ρ=4.15g/cm3. The results indicated that excess Na doping can make up for the Na volatilized while sintering under atmosphere pressure, but as x was 0.04, too much more Na dropping would lower the sintering temperature. Therefore, there would be quantities of liquid phases, as was shown in the fig.1(d), which caused the inferior properties of piezoelectric ceramics.

• Periodical: Materials Science Forum (Volume 859)
• Pages: 24-29
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.859.24
• Online since: May 2016
• Authors: Duo Zhao, Xing Hua Fu*, Guo Yuan Cheng, Wen Hong Tao, Yue Zhao, Li Ping Zhao, Wen Xin Ma
• Keywords: Excess Na-Doped, Microstructure, Piezoelectric Ceramics, Properties, Sol-Gel Method

References

[1] Weilie Zhong , Ferroelectricity Physics, Science press, (1996).

[2] Muyi Wu , The research progress of pizoelectric ceramics sintered at low temperature, China Science and Technology Information, 2010, (10): 153-154.

[3] X. Ye, Z. T. H. Tse, G. Tang, G. Song. Mechanical properties and phase transition of biomedical titanium alloy strips with initial quasi-single phase state under high-energy electropulses. Journal of the Mechanical Behavior of Biomedical Materials. 42 (2015).

DOI: 10.1016/j.jmbbm.2014.11.009

[4] X. Ye, L. Wang, Z. T. H. Tse, G. Tang, G. Song. Effects of high-energy electro-pulsing treatment on microstructure, mechanical properties and corrosion behavior of Ti–6Al–4V alloy. Materials Science and Engineering: C. 49 (2015) 851-60.

DOI: 10.1016/j.msec.2015.01.081

[5] JIANG Min-hong, DENG Man-jiao, YANG Zhu-pei, et al. Structure and piezoelectric properties of (1-x)K0. 5Na0. 5NbO3-xLiBiO3 lead-free piezoelectric ceramic[J]. Transaction of Nonferrous Metals Society of China, 2012, (22): 133-133.

DOI: 10.1016/s1003-6326(12)61697-5

[6] Zhao Jingbo, Du Hongliang, Qu Shaobo, et al. The effects of Bi(Mg2/3Nb1/3)O3on piezoelectric and ferroelectric properties of K0. 5Na0. 5NbO3lead-free piezoelectric ceramics[J]. Journal of Alloys and Compounds, 2011，(509): 3537–3540.

DOI: 10.1016/j.jallcom.2010.07.153

[7] F Rubio Marcos, J J Reinos, X Vendrell, et al. Structure, microstructure and electrical properties of Cu2+doped, (K, Na, Li)(Nb, Ta, Sb)O3piezoelectric ceramics[J]. Ceramics International, 2013, (39): 65–69.

DOI: 10.1016/j.ceramint.2012.10.270

[8] Xiong P, Tan G Q, Ren H J. Influence of Ta5+Doping on the Piezoelectric Properties of KNN Ceramics[J]. Key Engineering Materials, 2012, 512: 1399-1402.

DOI: 10.4028/www.scientific.net/kem.512-515.1399

[9] Huiqin Lv, Mingli Wu, etc. Research progress of KNN based lead-free piezoelectic ceramics[J], 2012 , 25(2): 44-47.