Microwave dielectric properties of (Mg_0.95Co_0.05)TiO₃-(Na_0.5Nd_0.5)TiO₃ ceramic system

The microwave dielectric properties and the microstructures of the (1 - x)(Mg_0.95Co_0.05)TiO₃-x(Na_0.5Nd_0.5)TiO₃ (0.1 ≤ x ≤ 0.18) ceramic system have been investigated. The two phase system was confirmed by XRD and EDX analysis throughout the entire experimental range. In this system, the microwave dielectric properties can be effectively controlled by varying the x value. The dielectric constant ranged from 18.3 to 25.4 as the x varies from 0.1 to 0.18. With the increase of sintering temperature, the Q × f increased to a maximum and decreased thereafter. A maximum Q × f ∼ 112,000 GHz (where f = 8.6 GHz, is the resonant frequency) was achieved for samples with x = 0.1. For practical applications, a new microwave dielectric material, 0.84(Mg_0.95Co_0.05)TiO₃-0.16(Na_0.5Nd_0.5)TiO₃, is suggested and possesses a good combination of dielectric properties: ε_r ∼ 24.39, Q × f ∼ 70,000 GHz, τ_f ∼ 1.6 ppm/°C. It is proposed as a suitable candidate dielectric for GPS patch antennas and passive components in wireless communication system.