Improving the breakdown strength of (Mg0.9Zn0.1)2(Ti1−xMnx)O4 ceramics with low dielectric loss

The phase composition, microstructure, dielectric properties and breakdown strength of (Mg0.9Zn0.1)2(Ti1−xMnx)O4 ceramics synthesized using a conventional solid-state reaction were investigated. The substitution of Ti4+ by Mn2+ can form a single spinel phase and result in a homogenous microstructure, which improves breakdown strength and reduces dielectric loss. Impedance spectroscopy results show that grain and grain boundary exhibit similar impedance properties and that the Schottky barrier in the grain boundary cannot be observed. When the x value is equal to 0.01, (Mg0.9Zn0.1)2(Ti1−xMnx)O4 ceramics with a high breakdown strength of 102 kV/mm (at 0.2 mm) and a low dielectric loss of 5.3×10−5 (at 6 GHz) can be obtained, which are beneficial in the development of high voltage solid-state pulse-forming lines.