Investigation of bismuth-based perovskite system:: (1-x)Bi(Ni2/3Nb1/3)O3-xPbTiO3 -: art. no. 034103

The dielectric and piezoelectric properties for bismuth-based perovskite system (1-x)Bi(Ni2/3Nb1/3)O-3-xPbTiO(3) (BNN-PT100x) with x=0.6-0.95 were investigated. High-density polycrystalline ceramics were fabricated using a conventional solid-state reaction method. Morphotropic phase boundary (MPB) at x=0.625-0.65 composition was observed by x-ray-diffraction measurements, separating rhombohedral and tetragonal phases. Analogous to Pb(ZrTi)O-3 ceramic, enhanced dielectric and piezoelectric activities were associated with the composition near the MPB. The dielectric constant (K-33(T)) and piezoelectric coefficient (d(33)) for BNN-PT65 composition were found to be 1100 and 140 pC/N, respectively, with a Curie temperature (T-c) around 273 degrees C. The addition of manganese (Mn) resulted in lowering the dielectric loss and increasing the mechanical quality factor Q when compared with the pure counterpart. The coercive field was found to increase to 30.7 kV/cm when BNN-PT65 was modified with magnesium (Mg). These results demonstrate the BNN-PT system to be a competitive piezoelectric material with a reduced lead content. (c) 2005 American Institute of Physics.