The Correlations between Complex Chemical Bond Theory and Microwave Dielectric Properties of Ca2MgSi2O7 Ceramics

Magnesium melilite (Ca2MgSi2O7) ceramic with tetragonal crystal structure was prepared through the conventional solid-state method. Crystal structure and complex chemical bond theory were used to analyze the microwave properties of Ca2MgSi2O7 ceramics and the correlations between the bond ionicity, lattice energy, bond energy and relative dielectric constant (epsilon(r)), quality factor (Qxf(0)), temperature coefficient of resonant frequency ((f)) were discussed in depth. Optimum microwave dielectric properties were obtained when sintered at 1300 degrees C for 4h: epsilon(r)=9.86, the dielectric loss (tan) was 1.24x10(-4) (at 1MHz), Qxf(0)=8016GHz (resonant frequency f(0)=7.90GHz), (f)=-42ppm/degrees C.