Research On The Microwave Dielectric Properties And Breakdown Strength Of Mg₂TiO₄-based Ceramics

Mg₂TiO₄-based ceramics were chosen as the research objective in this article. Ionsubstitution and oxide doping were used to adjust the microwave dielectric properties andthe breakdown strength of Mg₂TiO₄-based ceramics. ZBG and CBS frit were chosen todecrease the sintering temperature of ceramics.Mg₂TiO₄is a porous ceramic, in order to improve the sintering characteristics ofMg₂TiO₄-based ceramics, ZBG and CBS frits were doped into the material. ZBG frit canlower the densification temperature by about200℃. When2wt%is doped in theMg₂TiO₄-xwt%ZBG system, a ceramic with good microwave dielectric properties andbreakdown strength properties sintered at1300℃can be obtained. The CBS frit also candecrease the sintering temperature. When1wt%is doped in the Mg₂TiO₄-xwt%CBSsystem, a ceramic with good microwave dielectric properties and breakdown strengthproperties can be obtained. When the content of CBS frit is excess, it will deteriorate theproperties of the ceramics.In order to make the grain smaller and uniform, the MgO was doped in the Mg₂TiO₄material, and a certain mount of ZBG frit was doped. The effect of MgO on the phasecompositions, microstructures, microwave dielectric properties and the breakdownstrength of Mg₂TiO₄ceramics have been studied. The study shows that the doping ofMgO and ZBG frit improve the density and decrease the grain size. So in the guarantee ofgood microwave dielectric properties, we can get a good value of breakdown strength.（Mg0.9Zn0.1）2TiO₄was chosen as the based material. And the ZBG and CBS fritswere doped in the（Mg0.9Zn0.1）2TiO₄. The study on the ZBG doping shows that thesubstitution of Mg2+using Zn2+can decrease the grain size. When2wt%is doped in the（Mg0.9Zn0.1）2TiO₄-xwt%ZBG system, a ceramic with good microwave dielectricproperties sintered at1300℃can be obtained. Small grain is beneficial to the improvement of the breakdown strength, so the best breakdown strength value is obtainedat1275℃. The study on the CBS doping shows that the MgTiO3phase makes the ronthe high side. When1wt%is doped in the （Mg0.9Zn0.1）2TiO₄-xwt%CBS system, a ceramicwith good microwave dielectric properties and breakdown strength properties can beobtained.Under the previous experiments,（Mg0.9Zn0.1）2TiO₄-MgO-2wt%ZBG were chosen toresearch the influence of the thickness on the breakdown strength. The result shows thatthe breakdown strength rapidly reduces with the increase of the thickness. The data fittingresult is as follows: Eb=42.24*d^（-0.86） KV/mm.