Microwave dielectric properties of SnO2-doped CaSiO3 ceramics

Abstract: SnO2-doped CaSiO3 ceramics were successfully synthesized by a solid-state method. Effects of different SnO2 additions on the sintering behavior, microstructure and dielectric properties of Ca(Sn1−x Si x )O3 (x=0.5–1.0) ceramics have been investigated. SnO2 improved the densification process and expanded the sintering temperature range effectively. Moreover, Sn4+ substituting for Si4+ sites leads to the emergence of Ca3SnSi2O9 phase, which has a positive effect on the dielectric properties of CaO–SiO2–SnO2 materials, especially the Qf value. The Ca(Sn0.1Si0.9)O3 ceramics sintered at 1375°C possessed good microwave dielectric properties: ε r =7.92, Qf =58,000GHz and τ f =−42ppm/°C. The Ca(Sn0.4Si0.6)O3 ceramics sintered at 1450°C also exhibited good microwave dielectric properties of ε r=9.27, Qf=63,000GHz, and τ f =−52ppm/°C. Thus, they are promising candidate materials for millimeter-wave devices. [Copyright &y& Elsevier]