Preparation and Dielectric Properties of Ce-Doped Barium Strontium Titanate Nano-Powders

Citric acid and ethanol are attempted to prepare cerium doped barium strontium titanate (Ce-BST) nano-powders, and the structure and dielectric properties of the powders were studied. X-ray diffraction (XRD) shows that the powders are ABO(3) cubic perovskite structure almost with no second phase. Scanning electronic microscope (SEM) reveals that the powders calcined at 850 degrees C contain many spherical and loose soft conglobations composed of uniform grains with average size less than 100 nm. The powders display excellent dielectric properties with particularly low dielectric loss tangent of 0.002 due to Ce doping. The optimum dielectric properties were achieved at 900 degrees C with dielectric constant of 63.2 and dielectric loss of 0.003 at 1GHz. The powders can be fully satisfied the requirements in many applications like microwave devices. The effect of the calcination temperature and related mechanisms are discussed.