Dielectric properties and energy storage behaviors in ZnNb2O6-doped Sr0.97Nd0.02TiO3 ceramics

Using the solid-state ceramic route, Sr0.97Nd0.02TiO3 ceramics with addition of ZnNb2O6 were prepared, and the phase purity, microstructure, dielectric property and energy-storage performance were investigated. The XRD results suggest the formation of solid solutions for all the studied compositions. The SEM results show the moderate addition of ZnNb2O6 improves the sintering densification and microstructure of the ceramic samples. The breakdown strength (BDS) is notably improved due to the reduction of the grain size and dense uniform microstructure. And the highest BDS of 493 kV/cm can be achieved for the sample with 6 wt% ZnNb2O6 additive. The Sr0.97Nd0.02TiO3 ceramic with 6.0 wt% ZnNb2O6 addition shows the maximum theoretical energy-storage density of 2.37 J/cm3, which is 3.4 times higher than that of pure SrTiO3 in the literature. Therefore, the ZnNb2O6 doped Sr0.97Nd0.02TiO3 ceramics might be a kind of promising energy storage dielectric material.