Study of SrTiO3 powder morphology control and the influences on microstructure

• Main Authors: Wei-Lung Tzeng, 曾為隆
• Other Authors: Shao-Ju Shih
• Format: Others
• Language: en_US
• Published: 2016
• Online Access: http://ndltd.ncl.edu.tw/handle/7e843z

博士 === 國立臺灣科技大學 === 材料科學與工程系 === 104 === Microstructures of polycrystalline material relate with particle morphologies, structure and size distributions of starting powder. Hence this study synthesized SrTO3 powder by spray pyrolysis with various additives (citric acid, acetic acid and hydrogen peroxide) to manipulate particle morphologies, structures and size distributions. To characterize the physic properties of precursor solution, crystallographic structures of synthesized powder, particle morphologies and structures, thermogravimetric analysis, X-ray diffractometer, scanning electron microscopy and transmission electron microscopy were applied. According the experimental results and analyses, the mechanisms of particle formation were proposed. To investigate the influences of starting powder with various structures on sintering process, the synthesized SrTiO3 powders were sintered (1500 oC). Grain boundary orientations and grain sizes were carried out by electron backscatter diffraction technique; in addition, the conductivities were also measured under different temperatures. The results showed that the additives with OH groups reduce surface energy of (111) and crystal surfaces have more (111) orientation; furthermore, the crystal surfaces with (111) orientation induce Σ3 grain boundaries formation. The conductivity results indicate that the higher Σ3 grain boundary populations increase conductivity.