Low-temperature preparation and size effect of strontium barium niobate ultrafine powder

Ultrafine strontium barium niobate ((SrxBa1-x)Nb2O6, SBN) powders were prep ared using sol-gel and hydrolysis aging processes. Their structural propert ies were examined via X-ray diffractometry and Raman spectroscopy, Our resu lts indicated that the SBN powders crystallize to a pure tetragonal phase a t annealing temperatures as low as 700 degreesC, The crystallite size of SB N powders subjected to different thermal treatments was in the range of sev eral tens of nanometers. Differential scanning calorimetry revealed that th e heat flow had a broadened peak. The transition temperature from the ferro electric phase to the paraelectric phase and the relative dielectric consta nt of the SBN50 powder were less than the corresponding values of the bulk ceramic and the single crystal.