Effects of dwell time on dielectric properties and diffuse phase transition behavior of Li2CO3 doped BaZr0.2Ti0.8O3 ceramic

Li2CO3-doped lead-free Ba(Zr0.2Ti0.8)O3 (short as BZT20) ceramics were prepared by solid-state reaction method. The effect of dwell time (2–8 h) during sintering on the microstructure, dielectric properties and diffuse phase transition behavior of these samples is firstly investigated. All samples sintered at 1250 °C for different dwell time are of a pure perovskite phase. As the dwell time increased from 2 to 4, 6 and 8 h, the average grain size increased from ∼15 to ∼45 μm and decreased to ∼8 μm at 8 h dwell time. The samples sintered for 4 h showed enhanced dielectric property and lower diffusivity with εm = 15,756 and γ = 1.65. Moreover, the peak temperature Tm corresponding to the maximum value of the dielectric constant εm decreased slightly with the increase of dwell time, which may be attributed to the grain size effects on Li2CO3 doped BZT20 ceramics.