Enhanced dielectric breakdown strength in Ni2O3 modified Al2O3-SiO2-TiO2 based dielectric ceramics

Dielectric ceramics have raised particular interest since they enable pulsed-power systems to achieve high voltage gradient and compact miniaturization. In this work, x wt%Ni₂O₃ doped Al₂O₃-SiO₂-TiO₂ based dielectric ceramics were prepared using conventional solid-state reaction and the effects of Ni₂O₃ on the crystal structure, dielectric properties and dielectric breakdown strength were investigated. It was found that with the doping of Ni₂O₃, the Al₂O₃-SiO₂-TiO₂ based dielectric ceramics became denser and the distribution of each phase was more uniform. For the composition of x?=?2.0, the dielectric breakdown strength was increased into 82.1?kV/mm, more than twice compared with that of the undoped one. In addition, the relationship between the dielectric breakdown strength and the resistance of Al₂O₃-SiO₂-TiO₂ based dielectric ceramics was discussed. The results show that the doping of Ni₂O₃ is a very feasible way to improve the dielectric breakdown strength and optimize the dielectric properties for the Al₂O₃-SiO₂-TiO₂ based dielectric ceramics.