Preparation of SrBi4Ti4O15/Ag composites sintered at low temperature and their dielectric properties

Strontium bismuth titanate (SBTi) matrix composites containing Ag particles were synthesized by the conventional solid-state reaction method. The SBTi/Ag composites were characterized by a variety of techniques: x-ray diffraction, optical metallurgical microscope, scanning electron microscope and dielectric measurements. It is found that Ag doping has significant effect on the physical properties of the composites. With the addition of Ag particles to the SBTi matrix, the single-phase layered perovskite structure of the matrix is preserved and the sintering temperature of the system is lowered from 1 120 degrees C for monolithic SBTi to 950 degrees C. The SBTi/Ag composites show a significant change of the dielectric constant. With increasing Ag content, a gradual increase of the dielectric constant is observed and the dielectric losses of SBTi/Ag composites remain unchanged when the temperature is in the range from the room temperature to 200 degrees C, however, the Curie peak of dielectric constant is repressed. The results show that the SBTi/Ag composites improve the dielectric properties and the processing condition.