Influence of Properties of Bi_2(Zn_(1/3)Nb_(2/3))_2O_7 Ceramics Doped with Na-Ni

Bi_2(Zn_(1/3)Nb_(2/3))_2O_7 based ceramics were prepared by a traditional solid phase reaction method.The effects of substitution Na~+ for Bi~(3+) and Ni~(2+) for Nb~(3+) on the sintering and dielectric properties of Bi_2(Zn_(1/3)Nb_(2/3))_2O_7 based ceramics were investigated.The sintering temperature of the substituted samples dropped to 870℃from 960℃.At -30℃-+130℃,the dielectric relaxation peak with a broad temperature region is obviously observed and two relaxation peaks appear when the substitution of Ni~(2+) reaches 0.2.Then,with the increasing of substitution, the temperature of the permittivity maximum shifts to higher temperature and the activation energy involved in the relaxation processes increases and the distance between two relaxation peaks become longer.Defect dipole and distortion of crystal lattice theories are used to explain the dielectric relaxation of Na-Ni doped Bi_2(Zn_(1/3)Nb_(2/3))_2O_7ceramics.