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.