Study on the (1-x)(Mg_0.7Zn_0.3)TiO_3-x (Ca_0.61Nd_0.26)TiO₃ microwave dielectric ceramics

The microwave dielectric properties of the (1-x)(Mg_0.7Zn_0.3)TiO₃- x(Ca_0.61Nd_0.26)TiO₃(MZCNT) system were investigated. The system was prepared using a conventional solid-state ceramic route. The objective of the present work is to compensate for the negative temperature coefficient of resonant frequency (τ_f) of (Mg_0.7Zn_0.3) TiO₃ by the addition of (Ca_0.61Nd_0.26) TiO₃. The microwave dielectric properties are strongly correlated with the sintering temperature and the composition. Very dense MZCNT ceramics were synthesized by sintering at 1250°C, when sintered at temperatures above 1300°C, the decomposition of (Ca_0.61Nd_0.26) TiO₃ and evaporation of Zn resulted the decrease in density and degradation in dielectric properties. With increasing (Ca_0.61Nd_0.26) TiO₃, the dielectric constant (ε_r) increased and the quality factor Q×f decreased. For practical application, 0.87(Mg_0.7Zn_0.3) TiO₃- 0.13(Ca_0.61Nd_0.26) TiO₃ ceramics sintered at 1250°C with a dielectric constant ε_r~24.3, a Q×f value of 34000GHz and a temperature coefficient of resonance frequency (τ_f) of -9×10^-6/°C is proposed in this paper.