부산대학교 도서관

Abstract: Perovskite (1− x)(0.06BiYbO3–0.94Pb(Ti0.5Zr0.5)O3)–xLiNbO3 (BYPTZ-LN) ceramics were synthesized by the conventional ceramic processing. The effect of LiNbO3 on the microstructure and piezoelectric properties was investigated. The perovskite phase and the Yb2Ti2O7 pyrochlore phase are coexisting in the BYPTZ-LN ceramics sintered at 1140°C. The material with perovskite structure is tetragonal at x ≤0.04 and becomes single rhombohedral at x ≥0.08. A morphotropic phase boundary between rhombohedral and tetragonal phases is found in the composition range 0.04≤ x ≤0.08. Analogous to Pb(Zr,Ti)O3, the piezoelectric and electromechanical properties are enhanced for compositions near the morphotropic phase boundary. Piezoelectric constant d 33 values reach 290–360pC/N. Electromechanical coefficients k p reach 0.38–0.55. The maximum values of d 33, k p and P r are obstained as x =0.08, accompanying with the minimum values of Q m and E c. The Curie temperature T c and the maximum value of dielectric constant decrease with increasing LiNbO3 content. BYPTZ-LN ceramics with the high d 33 value and the high thermal-depoling temperatures of >320°C are obtained. [Copyright &y& Elsevier]