Structure, bond characteristics and Raman spectra of CaMg1-xMnxSi2O6 microwave dielectric ceramics

The CaMg1-xMnxSi2O6 (x = 0-0.08)ceramics were reported here for the first time. The relationships among structural characteristics, vibrational modes and dielectric properties for the ceramics were researched based on complex chemical bond theory and Raman vibrational spectroscopy. The formation of a single phase with clinopyroxene structure when x = 0 to 0.08 was detected by X-ray diffraction. The monotonous increase of epsilon(r) is ascribed to the average bond covalency, polarizability and Raman shift. The Q x f value is influenced by total lattice energy and full width at half maximum of Raman spectra which are both connected with the intrinsic loss. The variation of tau(f) is related to thermal expansion coefficient and M1 -site bond valence. Furthermore, the CaMg0.98Mn0.02Si2O6 ceramic sintered at 1300 degrees C possessed optimal microwave dielectric properties of epsilon(r) = 8.01, Q x f = 83469 GHz and tau(f) = - 45.27 ppm/degrees C.