Study on the (1-x)(Mg0.7Zn0.3)TiO3－x(Ca0.61Nd0.26)TiO3 Microwave Dielectric Ceramics

The microwave dielectric properties of the (1-x)(Mg0.7Zn0.3)TiO3－x(Ca0.61Nd0.26)TiO3(MZCNT) system were investigated. The system was prepared using a conventional solidstate ceramic route. The objective of the present work is to compensate for the negative temperature coefficient of resonant frequency (τf) of (Mg0.7Zn0.3)TiO3 by the addition of (Ca0.61Nd0.26)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℃, when sintered at temperatures above 1300℃, the decomposition of (Ca0.61Nd0.26)TiO3 and evaporation of Zn resulted the decrease in density and degradation in dielectric properties. With increasing (Ca0.61Nd0.26)TiO3, the dielectric constant (εr) increased and the quality factor Q×f decreased. For practical application, 0.87(Mg0.7Zn0.3)TiO3－0.13(Ca0.61Nd0.26)TiO3 ceramics sintered at 1250℃ with a dielectric constant εr～24.3, a Q×f value of 34000GHz and a temperature coefficient of resonance frequency (τf) of -9×10-6/℃ is proposed in this paper.