Phase controlled Raman modes and dielectric properties in (1-x)MgTiO3-x(Mg4Ta2O9)1/3

(1-x)MgTiO3-x(Mg4Ta2O9)1/3 (MTT in short) ceramics are prepared and the Raman modes and dielectric properties controlled by the phases were investigated. There are two solid solution regions (ss1: 0 ≤ x < 0.5; ss2: 0.8 < x ≤ 1) and one two-phase region (ss1+ss2: 0.5 ≤ x ≤ 0.8) in the MTT system sintered at 1400 °C. Raman modes and dielectric constant of MTT varies smoothly in the solid solutions, which agrees with the behavior of average crystal structures. The local Raman modes and line broadening of Raman peaks in solid solutions indicate local deviation from the average structures. By reasonable simplification, the intrinsic dielectric constant ε′r is proportional to quadratic x in solid solution regions and proportional to linear x in two-phase region, which is helpful for the development of dielectric materials.