Enhanced Crystallization Behaviour and Microwave Dielectric Properties of 0.9CaMgSi(2)O(6)-0.1MgSiO(3) Glass-Ceramics Doped with TiO2

The dependence of the microwave dielectric properties of the glass-ceramic composite 0.9CaMgSi(2)O(6)-0.1MgSiO(3) on the crystallization behaviour was investigated as functions of the TiO2 content and heat-treatment temperature. The crystallization behaviour of the specimens was evaluated via a combination of the Rietveld and reference-intensity ratio methods. For specimens with a TiO2 content of up to 1 wt.%, a monoclinic diopside phase was formed, whereas a secondary TiO2 phase was formed with further increases in the TiO2 content. The quality factor (Qf) of the specimens was strongly dependent on the degree of crystallization. The highest Qf value was obtained with a TiO2 content of 0.5 wt.%, which was improved by increasing the heat-treatment temperature. The dielectric constant (K) was affected by the size of the crystallites and the TiO2 content. The temperature coefficient of the resonant frequency (TCF) was nearly constant for all of the specimens, regardless of the TiO2 content or heat-treatment temperature.