Fabrication and characterization of binary piezoelectric (Bi 1/2Na1/2)TiO3-Ba(Cu1/3Nb 2/3)O3 solid solutions

Abstract

Perovskite-structured solid solutions with compositions of 0.9963{(1 - x)(Bi1/2Na1/2)TiO3-xBa(Cu 1.1/3Nb2/3)O3} + 0.0037MnO2, with x = 0{0.06 [abbreviated as (1 - x)BNT-xBCN)], were fabricated by normal sintering, and their structural, and piezo- and ferroelectric properties were investigated in detail. The X-ray diffraction profiles of the (1 - x)BNT-xBCN solid solutions with x = 0{0.06 suggested that the rhombohedraltetragonal morphotropic phase boundary (MPB) in this material system is in the compositional region x = 0.0425{0.0460. The cross-sectional transmission electron microscopy (TEM) images and selected-area electron diffraction (SAED) patterns of the (1 - x)BNT-xBCN samples with x = 0.0475 suggested that the present materials have a modulation structure arranged by a double period along the [111] direction. It is shown that the tetragonal BNT-BCN (x = 0.0475) solid solution with a composition of 0.9490BNT.0.0473BCN.0.0037MnO2 near the MPB has a piezoelectric coefficient (d33), a relative permittivity (ε33T=ε0), and a remanent polarization (Pr) of approximately 1.8, 3.2, and 2.8 times larger, respectively, than those of the BNT solid solution without BCN substitution. © 2011 The Japan Society of Applied Physics.