Phase Evolution and Dielectric Properties of (Mg _0.95 M _0.05 ²⁺ )Ti ₂ O ₅ (M ²⁺ =Co, Ni, and Zn) Ceramics at Microwave Frequencies

Abstract

Being the second phase in the (Mg 0.95 M 0.05 2+ )Ti 2 O 5 (M 2+ =Co, Ni, and Zn) ceramics, the sintering behavior and microwave dielectric properties of specimens using (Mg 0.95 M 0.05 2+ )Ti 2 O 5 were investigated. (Mg 0.95 M 0.05 2+ )Ti 2 O 5 solid solutions were detected throughout the entire experiment. Lattice parameters were also measured for specimens with different M 2+ to confirm the formation of solid solutions. The sintering temperature of (Mg 0.95 Co 0.05 )Ti 2 O 5 was 25°C lower than those of the others. The (Mg 0.95 M 0.05 2+ )Ti 2 O 5 ceramics, in this study, acquired the following microwave dielectric properties: ɛ r of 16–18.5, Q × f of 28 000–68 000 GHz, and τ f of −38∼−47 ppm/°C. Compatible ɛ r and τ f values were obtained in comparison with that of (Mg 0.95 M 0.05 2+ )TiO 3 ceramics. However, it showed a much lower Q × f , indicating that the formation of (Mg 0.95 M 0.05 2+ )Ti 2 O 5 in the (Mg 0.95 M 0.05 2+ )TiO 3 ceramics would cause a drastic reduction in the Q × f value.