MA Jinming, ZHANG Qunfei, XIAO Changjiang
(Department of Material Science and Engineering, Henan University of Technology, Zhengzhou, 450001, Henan, China)
Abstract: Barium titanate-based ceramics with different contents of Bi(Ni0.5Zr0.5)O3 were prepared by using twice sintering and solid-state reaction and the crystal structure, while microstructure and dielectric properties of the samples were studied. It is found that the (1−x)BaTiO3-xBiBi(Ni0.5Zr0.5)O3 (BNZ, x=0.05, 0.10, 0.15) ceramics have perovskite structure. According to XRD and Raman measurements, phase transform from tetragonal to pseudo-cubic at x=0.10, whereas grain size of the BT-0.10BNZ ceramics is about 1.54 m. With increasing frequency, the dispersion phase transition behavior and frequency dispersion phenomena of the BT-0.10BNZ ceramics, such as the dielectric constant peak shifting to low temperature and peak broadening, were found, indicating that the ceramics have successfully transformed from ferroelectrics to relaxor ferroelectrics. The doped ceramics have a high dielectric constant εr of ~ 3868 and high temperature stability of Δε/ε25 ℃ ≤ ±15% (−77 –200 ℃).
Key words: BT-xBNZ ceramic; doping; crystal structure; relaxation ferroelectrics; dielectric properties