Dielectric properties of xNa0.5Bi0.5TiO3–(1−x)Ba0.66Mg0.04Sr0.3TiO3 composite ceramics
Abstract
The ceramics with the composition of xNa0.5Bi0.5TiO3–(1−x)Ba0.66Mg0.04Sr0.3TiO3 (NBT–BMST) in which x = 0.2, 0.3, 0.4 and 0.5 were prepared successfully by the solid-state reaction method. The effects of NBT-doping on phase structure, morphology, temperature stability and dielectric properties had been investigated in detail. The XRD results show that the composites are composed of tetragonal perovskite. The phase structure of NBT–BMST is observed by scanning electron microscopy. The dielectric constant of 0.3Na0.5Bi0.5TiO3–0.7Ba0.66Mg0.04Sr0.3TiO3 ceramic is ∼4100, the temperature coefficients of capacitance are −15%, 15% and 22% at −55∘C, 60∘C and 200∘C, respectively. And the dielectric loss is less than 0.13, which is obviously superior to other compositions. The results of this work showed that the component of 0.3Na0.5Bi0.5TiO3–0.7Ba0.66Mg0.04Sr0.3TiO3 is a promising candidate to high-temperature stable materials.
