Lattice vibrational characteristics and dielectric properties of pure phase CaTiO_3 ceramic

摘要

CaTiO_3 microwave dielectric ceramic was fabricated utilizing traditional two-step sintering process. XRD pattern analysis after Rietveld refinement indicated a pure phase CaTiO_3 sample. SEM image illustrated well-crystallized sample with uniform grain sizes and clear grain boundaries. The lattice vibrational characteristics were analyzed by Raman and IR spectroscopy, and the intrinsic properties were calculated in conjunction with the semi-quantum four-parameter (FPSQ) model, which turned out that the low-frequency vibrational modes contribute the most to the dielectric properties. Besides, the real and imaginary parts of the dielectric function were drawn from the FPSQ model. The intrinsic property results fitted from the FPSQ model agree well with the measured values.