Bi0.5(Nal-x-yKxLiy)0.5TiO3 Lead-free Piezoelectric Ceramics and Their Applications for Buzzers and Filters

• Main Authors: Ding-quan Xiao, Jian-guo Zhu, Dun-min Lin, Ping Yu, Yan Zhuang, Qun Wei, Ling-zhi Li, Yunwen Liao, Jiagang Wu
• Format: Conference Proceeding
• Language: English
• Subjects: Bi 0.5 (Na 1-x-y K x Li y ) 0.5 TiO 3; Bismuth; buzzer; ceramic filters; Ceramics; Environmentally friendly manufacturing techniques; Filters; Frequency; Lead compounds; lead-free piezoelectric ceramics; Materials science and technology; Piezoelectric materials; Powders; Temperature dependence
• ISSN: 1099-4734; 2375-0448
• DOI: 10.1109/ISAF.2006.4387855

The new system of (BNKLT-x/y) lead-free piezoelectric ceramics, which were prepared by using conventional oxide mixing processing, were invented in our group. The ceramics show excellent piezoelectric and ferroelectric properties: d 33 =231 pC/N, k P =41.0%, k t =50.5%, P r =40.2 muC/cm 2 , and E c =2.47 kV/mm, respectively. The dependence of P-E loops on temperature reveals that the depolarization temperature T d of BNKLT-0.15/0.075 ceramics, which simultaneously have good piezoelectric properties (d 33 =164 pC/N, k p =36.3%, k t =48.6%) and strong ferroelectricity (P r =38.8 mu C/cm 2 , E c =3.73 kV/mm) at room temperature, is about 195degC. The ceramics were used for making buzzers by ordinary techniques as used for PZT-based buzzers, and the measurement of the electric-acoustic properties shows that the buzzers possess a very high sound pressure (~90 dB). The ceramics invented were also used for making middle frequency piezoelectric ceramic filters.