Low-Temperature Preparation and Size Effect of Strontium Barium Niobate Ultrafine Powder

Ultrafine strontium barium niobate ((SrxBa1-x)Nb2O6, SBN) powders were prepared using sol-gel and hydrolysis aging processes. Their structural properties were examined via X-ray diffractometry and Raman spectroscopy. Our results indicated that the SBN powders crystallize to a pure tetragonal phase at annealing temperatures as low as 700 °C. The crystal-lite size of SBN powders subjected to different thermal treatments was in the range of several tens of nanometers. Differential scanning calorimetry revealed that the heat flow had a broadened peak. The transition temperature from the ferro-electric phase to the paraelectric phase and the relative dielectric constant of the SBN50 powder were less than the corresponding values of the bulk ceramic and the single crystal.