Enhanced Electrical Properties of 3-0 Type Na0.5Bi2.5Nb2O9-BaTiO3 Composite High-Temperature Piezoelectric Ceramics (original) (raw)

(1-x)Na 0.5 Bi 2. 5Nb 2 O 9-xBaTiO 3 (NBN-BT, x = 0~0.15) 3-0 type composite high-temperature piezoelectric ceramics with T c values over 680 º C are prepared by solid state reaction method. Structural analysis demonstrates that nanosized BaTiO 3 (TB) is preferable to form solid solution with NBN matrix and the solid solution limit of NBN and BT is about x = 0.08. When x > 0.08, BaTiO 3 has a great effect on the grain growth during sintering and a secondary phase appears at the grain boundaries to form NBN-BT composite ceramics. The d 33 values and electrical resistivity of NBN-BT composite ceramics are about 50% and 1~2 orders of magnitude higher than those of pure NBN ceramics, due to the substitution induced piezoactivity from the rotation/tilting of oxygen octahedral and the formation of solid solution promoting the densification sintering, respectively. Therefore, a compromise between enhanced electrical resistivity, large d 33 and high T c , has been achieved by the formation of appropriate composites, which could shed light on how to obtain novel Aurivillius ferroelectrics for practical high-temperature applications.