Lattice vibrational characteristics and structure-property relationships of Ca(Mg1/2W1/2)O3 microwave dielectric ceramics with different sintering temperatures

Ca(Mg1/2W1/2)O3 (CMW) microwave dielectric ceramics were synthesized by the solid state reaction method and were sintered at the temperatures in the range of 1450-1550 degrees C for 4 h. X-ray diffraction and Rietveld refinement results confirmed that the main phase of the samples belongs to the monoclinic crystal structure (P21/c space group). The vibrational modes were determined using the Raman scattering and Fourier transform infrared reflection (FTIR) spectra, and the lattice vibrational characteristics were revealed in detail. The fitting curves of FTIR spectra were obtained by the four-parameter semi-quantum model that was used to calculate the intrinsic properties of samples, and the influence of the infrared mode on the intrinsic properties was elucidated. The structure-property relationships were constructed based on the Raman modes. The optimal dielectric properties of CMW ceramics are of epsilon r = 18.37, tan delta = 2.71 x 10-4 and were obtained for the sintering temperature of 1500 degrees C.