Studieson the (1― x)Mg0.7Zn0.3TiO3―xCa0.61La0.26TiO3Microwave Dielectric Ceramics System

The microstructures and the microwave dielectricproperties of the (1? x)(Mg0.7Zn0.3)TiO3― xCa0.61La0.26TiO3(MZT―CLT) ceramic system were investigated. The objective of the presentwork is to compensate for the negative temperature coefficient of resonantfrequency of (Mg0.7Zn0.3)TiO3 by the additionof (Ca0.61La0.26)TiO3. MZT―CLTceramics exhibited mixed phases of (Mg0.7Zn0.3)TiO3as the main phase associated with minor phases of Ca0.61La0.26TiO3 and (Mg0.7Zn0.3)Ti2O5.The microwave dielectric properties are strongly correlated with the sinteringtemperature and the composition. Very dense MZT―CLT ceramics were synthesizedby sintering at1275 . When the samples were sintered at temperaturesabove1300 , the evaporation of Zn resulted the decrease indensity and degradation in dielectric properties. With the increasing of x, the relative dielectric constant ( εr) of the ceramicsincreases and the product of quality factor and resonant frequency ( Q · f) decreases. The εr, Q· fand temperature coefficient of resonant frequency ( τf) of 0.87(Mg0.7Zn0.3)TiO3―0.13Ca0.61La0.26TiO3ceramic sintered at1275 are 26, 86000 GHz and ―6×10 ― 6 / , respectively.