Dielectric properties of (Na0.5Bi0.5)TiO3–Ba0.7Sr0.3Sn0.02Ti0.98O3 composite ceramics

Abstract

Lead-free [Formula: see text]Na[Formula: see text]Bi[Formula: see text]TiO3–[Formula: see text]Ba[Formula: see text]Sr[Formula: see text]Sn[Formula: see text]Ti[Formula: see text]O3 (NBT–BSST) ceramics are prepared by a wet solid-phase reaction method. The effect of NBT/BSST ratio on phase structure, microstructure and dielectric properties has been investigated in detail. The X-ray diffraction (XRD) analysis illustrates that the composites are composed of tetragonal perovskite. With increasing NBT content, the ceramic capacitors display stronger temperature stability in its dielectric behavior. A great enhance of dielectric properties and other electric parameters is obtained in this system by properly modulating the compositions. For example, the composite ceramics with 30% NBT content possess a large dielectric constant [Formula: see text] of 3200 and a low dielectric loss [Formula: see text] of 0.09. The temperature coefficient of capacitance of NBT–BSST varies from −50% to 20% while the NBT content is 30% at the whole range of measured temperature. The results show that NBT–BSST ceramics are a good candidate of lead-free dielectric materials.