Dielectric and ferroelectric properties of Pb(Ni1/3Nb2/3)O3-Pb(Zn1/3Nb2/3) O3-PbTiO3 ternary ceramics

Ternary ceramics with the type of (1-x)(0.64PNN-0.36PT)-x(0.91PZN-0.09PT) (x= 0-0.82) were synthesized by the columbite precursor method. X-ray diffraction results demonstrate that all the samples lie within the morphotropic phase boundary (MPB) region in the pure perovskite structure except for the composition with x =0.82. The dielectric and ferroelectric properties of compositions with x=0-0.75 were investigated in detail. All the tested compositions show dielectric behaviors of frequency dispersion and diffuse phase transition. The Ni-rich compositions exhibit superior dielectric and ferroelectric properties to those of Ni-poor ones. The composition with x=0.15 has the maximum peak dielectric constant (23,410) at 1 kHz and the maximum remnant polarization (14.8 (mu)C/cm^2) with the driving electric field at 10 kV/cm. The variation of peak dielectric constant with x can be explained in terms of the product rate of the polar microregion in the materials.