Piezoelectric and dielectric properties of the Pb1-3×/2 Bix[(Ni1/3Nb2/3)0.4(Ti yZr1$ -y)0.6]O3 ceramics

In this paper, the structural, dielectric and piezoelectric properties of (Pb_1-2x/3Bi_x)[(Ni_1/3Nb _2/3) (Ti_yZr_1-y)]O_x(x=0~0.02,y=0.58~0.62) system have been investigated with the TiO₂/(TiO₂+ZrO₂) ratio and the substitution of Bi⁺³. With increasing the substitution of Bi ⁺³ morphotropic phase boundary shifts from the x=0, y-0.61 composition to the x-0.01, y-0.39 composition, Zr-rich region. The dielectric constant is enhanced with the increase of the Bi⁺³ substitution, and show the maximum value of 5032 at the x=0.01, y=0.59 composition. Increasing the substitution of the Bi⁺³, the electromechanical coefficients (k_pk₃₁) increase up to the substitution of 1.0 mol% Bi⁺³ and show the highest value of 0.667, 0.449 at the x=0.01, y=0.59 composition. The piezoelectric constants (d₃₃,d₃₁) have the highest value of 825, 344 at the x=0.05, y=0.6 composition because of the increase of the dielectric constant and the enhancment of the electromechanical coupling factor due to the transfer of crystal structure to MPB by the substitution of 0.5 mol% Bi⁺³, and the magnitude of butterfly-type strain shows the maximum value of 1200(*10^-6Δl/1) at the same composition