Lattice vibrational characteristics, dielectric properties and structure-property relationships of (1-x)SrWO4-xTiO2 composite ceramics

Abstract

Abstract (1-x)SrWO4-xTiO2 (x\xa0=\xa00, 0.05, 0.10, 0.15, 0.20, 0.25) were prepared by a conventional solid-state sintering method. The X-ray diffraction and Rietveld refinement data show that the SrWO4 phase can coexist with the TiO2 phase to form composite ceramics. Scanning electron microscopies show that the samples have dense and uniform particles. The lattice vibration properties were analyzed in detail by Raman and Infrared spectra. The intrinsic properties calculated by the FPSQ model based on FTIR spectra agree well with the results derived from the Clausius-Mossotti and damping equations. There is a positive relativity between the Raman shifts of the v1(Ag) modes and the permittivities, while a negative relativity exists between the full width at half-maximum values of the Bg modes and the dielectric losses. The measured dielectric constant values of SWT ceramics are between 7.05 and 9.30, the range of quality factor is 7669–63232\xa0GHz, and the τf values of which are between −24.44 and −84.37\xa0ppm/°C. Among them, when x\xa0=\xa00.15, the SWT ceramics achieved the most excellent dielectric properties with er\xa0=\xa08.06, Q\xa0×\xa0f\xa0=\xa042,617\xa0GHz (f\xa0=\xa015.70\xa0GHz), τf\xa0=\xa0−35.07\xa0ppm/°C.