Structure, dielectric, and ferroelectric properties of Ni doping on Ba${}_{0.85}$Ca${}_{0.15}$Zr${}_{0.1}$Ti${}_{0.9}$O${}_3$ ceramics

A series of Ba${}_{0.85}$Ca${}_{0.15}$Zr${}_{0.1}$Ti${}_{1-x}$Ni${}_x$)${}_{0.9}$O${}_3$ (BCZT-xNi) (x = 0, 0.01, 0.02, 0.04) ceramics were prepared by the sol-gel method. The XRD results demonstrate that there is no secondary phase, revealing that Ni completely entered the unit cell to form a solid solution. The microstructures for Ni-doped BCZT ceramics show the average grain size decreases significantly with the increase of Ni content. When x = 0.01, the sample shows relatively high dielectric constant (ε${}_r$ ∼ 4473) and good frequency stability, and low dielectric loss at 10${}^2$ Hz (tan δ ∼ 0.004). Influenced by doping Ni, the Curie temperature decreases and the diffusion phase transition increases. The hysteresis loop becomes slimmer and residual polarization is reduced. The sample of x = 0.02 shows an energy density of 0.18 J/cm${}^3$ and an energy efficiency of 70.12%. From the present work, cation replacement is an effective way to adjust its ferroelectric, dielectric, and energy storage properties.