DENSIFICATION AND MICROSTRUCTURAL DEVELOPMENT OF THE REACTION SINTERING OF STRONTIUM BARIUM NIOBATE

SrNb2O6 and BaNb2O6 were selected as the precursor powders for the rea ction sintering of strontium barium niobate of the composition SrxBa1- xNb2O6 (x = 0.5 and 0.6) (SBN). In comparing the densification behavio r of the reaction sintering and the normal sintering of SBN, it was ob served that the densification rate of the former was slower during rea ction but became faster after reaction. It was also found that the che mical reaction occurred prior to densification, but a high-density and uniform microstructure could be obtained for the reaction-sintered sa mple. The densification rate of the reaction-sintered sample was prono uncedly enhanced when the reaction was almost completed. We also propo sed the reason for the enhancement of the densification rate of the re action-sintered sample when the reaction was almost completed. A high- density (>98% of the theoretical density), uniform, and fine-grained ( 3-4 mu m) SBN microstructure could be achieved by using reaction sinte ring.