부산대학교 도서관

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.ceramint.2009.03.045 Byline: Gao Feng, Deng Zhenqi, Yang Le, Cheng Lihong, Tian Changsheng Keywords: Piezoelectric ceramics; Curie temperature; Pyrochlore phase; C. Electrical properties Abstract: Perovskite (1- x)(0.06BiYbO.sub.3-0.94Pb(Ti.sub.0.5Zr.sub.0.5)O.sub.3)-xLiNbO.sub.3 (BYPTZ-LN) ceramics were synthesized by the conventional ceramic processing. The effect of LiNbO.sub.3 on the microstructure and piezoelectric properties was investigated. The perovskite phase and the Yb.sub.2Ti.sub.2O.sub.7 pyrochlore phase are coexisting in the BYPTZ-LN ceramics sintered at 1140[degrees]C. The material with perovskite structure is tetragonal at x [less than or equal to]0.04 and becomes single rhombohedral at x [greater than or equal to]0.08. A morphotropic phase boundary between rhombohedral and tetragonal phases is found in the composition range 0.04[less than or equal to] x [less than or equal to]0.08. Analogous to Pb(Zr,Ti)O.sub.3, the piezoelectric and electromechanical properties are enhanced for compositions near the morphotropic phase boundary. Piezoelectric constant d.sub.33 values reach 290-360pC/N. Electromechanical coefficients k.sub.p reach 0.38-0.55. The maximum values of d.sub.33, k.sub.p and P.sub.r are obstained as x =0.08, accompanying with the minimum values of Q.sub.m and E.sub.c. The Curie temperature T.sub.c and the maximum value of dielectric constant decrease with increasing LiNbO.sub.3 content. BYPTZ-LN ceramics with the high d.sub.33 value and the high thermal-depoling temperatures of >320[degrees]C are obtained. Author Affiliation: College of Material Science and Engineering, Northwestern Polytechnical University, Xi'an, 710072, China Article History: Received 10 December 2008; Revised 10 January 2009; Accepted 28 March 2009