Nickel Doping Effects on the Structural and Dielectric Properties of Ba(Zn_1/3Nb_2/3)O₃ Perovskite Ceramics

The effects of nickel doping into Ba(Zn_1/3Nb_2/3)O₃ (acronym: BZN) ceramics is structurally, morphologically and electrically investigated. The nickel substitution in sites of Zn which was carried out by the solid state reaction technique strongly enhanced the structural, morphological and electrical performances of the BZN. Specifically, while the lattice constant and crystallite sizes increased, the microstrain and the defect density decreased. The relative density of the BZN ceramics increased from 95.40% to 98.24% upon doping of Ni with content of x = 0.05. In addition, the Ni doping increased the values of electrical conductivity without significant changes in the dielectric constant values. It is also observed that the doping the BZN ceramics highly altered the temperature dependent variation of the relative dielectric constant. In the temperature range of 293–473 K, the x = 0.05 Ni doped BZN samples were less sensitive to temperature. The dynamics of the temperature dependent dielectric response is dominated by the coupled defects excitation mechanisms. Both of the temperatures and frequency dependent dielectric constant, dielectric loss and electrical conductivity suggests that the Ni doped Ba(Zn_1/3Nb_2/3)O₃ ceramics is more appropriate for electronic device fabrication than the pure ones.