Phase, microstructure, and microwave dielectric properties of a new ceramic system: (1 − x)Mg(Ti0.95Sn0.05)O3–xCaTiO3

The microwave dielectric properties and microstructure of the new ceramic system (1 − x )Mg(Ti 0.95 Sn 0.05 )O 3 – x CaTiO 3 (0.02 ≤ x ≤ 0.08) prepared via a mixed-oxide route were investigated. To attain a temperature-stable material, CaTiO 3 was added to Mg(Ti 0.95 Sn 0.05 )O 3 as a temperature coefficient of resonant frequency ( τ f ) compensator. The compositions with 0.02 ≤ x ≤ 0.08 resulted in a mixture of two phases, Mg(Ti 0.95 Sn 0.05 )O 3 and CaTiO 3 , as confirmed by X-ray diffraction and energy-dispersive X-ray spectroscopic analyses. The values of the dielectric constant ( e r ) and the τ f of the ceramics were found to increase, and the unloaded quality factor ( Q u f o ) was found to decrease with increasing x values (i.e., increasing CaTiO 3 content). Excellent microwave dielectric properties of e r ≈ 21.5, Q u f o ≈ 112,500 GHz (at 9 GHz), and τ f ≈ 1.1 ppm/°C were attained for the 0.94{Mg(Ti 0.95 Sn 0.05 )O 3 }–0.06CaTiO 3 ceramic sintered at 1375 °C for 4 h.