Grain Growth and Electrical Properties of Strontium Barium Niobate

• Main Authors: Chen, Edin, 陳一塵
• Other Authors: Tsang-Tse Fang
• Format: Others
• Language: zh-TW
• Published: 1998
• Online Access: http://ndltd.ncl.edu.tw/handle/39381784511192277876

碩士 === 國立成功大學 === 材料科學(工程)學系 === 86 === Partial decomposition of SrxBa1-xNb2O6 powder due to ball milling effect has been investigated. The X-ray diffraction(XRD) measuments showed that except SBN 30&40, the other compositions of SBN have partially decomposed and the higher the ratio of Sr/ Ba, the more amount it decomposes. This phenomena was considered to be caused by the strain energy due to the ball milling. The relationship between partial decompositon and abnormal grain growth was studied. The comparisons of the SBN60 samples were sintered at 1300oC w/o pre-treatment after ball milling and, in which abnormal grain growth occurred in the samples without pre- treatment but not in the pre-treated samples. Further examination of the microstructures using TEM indicated that liquid phase might develop during sintering. XRD measuments showed the decomposed phase remaining for sample heated at 1300oC but not in pre-treated samples. Therefore, it is suggested that the development of the liquid phase might be due to the nonstoichiometric decomposed phase via the effect of ball milling. The grain growth kinetics of SBN50 at 1275oC time has the form of G4-G04=Kt fitted by the experimental data. However, grain growth of SBN60 was not obviously at 1275oC until 48h.After 48h, the abnormally large grain were observed in SBN60.It was suggested that this abnormal grain growth was due to the anisotropy of the grain boundary mobility. Finally, The dielectric behavior of SBN50&60 were studied. The equivalent circuit was used to fit the frequency dependent dielectric behavior and describe the relaxation behavior.