Structure and electrical behavior of unpoled and poled 0.97(Bi 0.5 Na 0.5 ) 0.94 Ba 0.06 TiO 3 -0.03BiAlO 3 ceramics

• DOI: 10.1016/j.matchemphys.2017.09.038
• Publication Date: 2017-09-18T15:30:34Z
• Authors: Yan-zi Qiu; Xiao-ming Chen; Han-li Lian; Jia-ping Ma; Wan-qing Ouyang
• Keywords: Poling; Tetragonal crystal system; Phase boundary

Abstract The ceramics (Bi 0.5 Na 0.5 ) 0.94 Ba 0.06 TiO 3 (BNBT) and 0.97BNBT-0.03BiAlO 3 (BNBTA/0.03) were synthesized via a solid-state reaction method. Effects of electric poling and Al 3+ -doping on structure and electrical behavior of BNBT and BNBTA/0.03 were studied. The results of Raman spectroscopy and X-ray diffraction confirm lattice distortion due to the doping of Al 3+ . BNBT and BNBTA/0.03 exhibit pure phase and dense microstructures. The tetragonal-rhombohedral morphotropic phase boundary exists in both samples. Electric poling causes an increase in the amount of the tetragonal phase. Dielectric behavior is sensitive to the electric poling and Al 3+ -doping. Compared to BNBT, BNBTA/0.03 exhibits pinched polarization loops, current-electric field curves with four peaks, and higher normalized piezoelectric constant. Based on the results of ultraviolet–visible diffuse reflectance spectra, electric conductivity, and Rayleigh analysis, it is suggested that the differences in electrical behavior between BNBT and BNBTA/0.03 are related to oxygen vacancies.