Lead-Free Piezoelectric Ceramic Based on (Bi 1/2 Na 1/2 )TiO 3-(Bi 1/2 K1/2 )TiO 3-BaTiO 3 Solid Solution
Yuji Hiruma, Y oichi Makiuchi, Rintaro Aoyagi, Hajime Nagata and T adashi T ak enak a** Author for corresponding; e-mail address: tadashi@ee.noda.tus.ac.jp
Volume: Vol.32 No.3 (SEPTEMBER 2005)
Research Article
DOI:
Received: -, Revised: -, Accepted: -, Published: -
Citation: Hiruma Y., Makiuchi Y.O., Aoyagi R., Nagata H. and A T.A.T.A.E., Lead-Free Piezoelectric Ceramic Based on (Bi 1/2 Na 1/2 )TiO 3-(Bi 1/2 K1/2 )TiO 3-BaTiO 3 Solid Solution, Chiang Mai Journal of Science, 2005; 32(3): 253-260.
Abstract
Piezoelectric properties of a solid solution based on three components of bismuth sodium titanate, (Bi1/2Na1/2)TiO3(BNT), bismuth potassium titanate, (Bi1/2K1/2)TiO3(BKT), and barium titanate, BaTiO3 (BT), that is, x(Bi1/2Na1/2)TiO3-y(Bi1/2K1/2)TiO3-zBaTiO3 [abbreviated to BNBKy:z(x); y:z=2:1, 4:1 and 10:1, x+y+z=1] are studied as a lead-free piezoelectric material. The highest electromechanical coupling factor, k33, and piezoelectric constant, d33, were 0.56 and 186 pC/N for BNBK2:1(0.878), 0.56 and 191 pC/N for BNBK4:1(0.852), and 0.52 and 180 pC/N for BNBK10:1(0.826). Nevertheless, the second phase transitions, T2, of these compositions are about 120ºC. The T2s shift to higher temperatures with decreasing the amount (x) of BNT content. Finally, the T2 higher than 200ºC was obtained with x £ 0.75, that the k33 and d33 for BNBK2:1(0.75) and BNBK4:1(0.75) were 0.44 and 116 pC/N, and 0.45 and 134 pC/N, respectively.