Effects of BaWO4 additive on Raman phonon modes and structure–property relationship of Ba(Mg1/3Ta2/3)O3 microwave dielectric ceramics

Abstract

Ba(Mg1/3Ta2/3)O3–BaWO4 (BMT–BW) microwave dielectric ceramics were synthesized using the conventional solid-state sintering technique. Effects of BW additive on Raman phonon modes and structure–property relationship of BMT ceramics were evaluated. The results show that increasing BW contents affect the crystal structures and dielectric properties of BMT ceramics greatly. The lattice parameters (a, c) gradually decrease with the increasing of W6+ content; the lattice parameter ratio (c/a) and the ordering degree reach a maximum value at x=0.04, and then gradually decrease with W6+ concentration. Studies about Raman spectra show that the peak frequencies of A1g(O) modes near 795cm−1 and Eg(O) modes near 158cm−1 and 430cm−1 reach a maximum value at x=0.04; the peak frequencies of Eg(Ta) modes near 210cm−1 reach a minimum value at x=0.04. The relationship between crystal structures and dielectric properties were finally established with vibration modes as the media.