Effect of additives on microwave dielectric properties in low-temperature firing (Mg,Ca)TiO₃ based ceramics

Abstract

Development of microwave dielectric high Q value in the frequency range of above 10 GHz is very important in the advancement of new media, such as satellite communication and broad-casting systems. For this purpose, a number of materials have been investigated and developed. Among these materials, the ilmenite type titanates (MTiO₃: where M=Mg, Mn) have high Q value and low dielectric constant due to the isolation of TiO₆ octahedra by the MO6 octahedron layer and cation vacancy layer in comparison with the perovskite titanates.

In this study, the microwave dielectric characteristics of low-temperature firing (Mg,Ca)TiO₃ ceramics with additives such as B₂O₃ and V₂O₅ have been investigated. For the (Mg_0.95Ca_0.05)TiO₃ compound added 5mol% B₂O₃ fired at 1200°C shows a maximum Qf value of 86000 GHz, dielectric constant of 19.6 and τ_f of −2.99 ppm/K.