|About this Abstract
||Materials Science & Technology 2009
||Characterization and Modeling of Ceramic-Ceramic and Metal-Ceramic Interfaces
||Structures of Low-Angle Grain Boundaries and Dopant Segregations in Alumina
||Eita Tochigi, Naoya Shibata, Atsutomo Nakamura, Takahisa Yamamoto, Yuichi Ikuhara
|On-Site Speaker (Planned)
Since low-angle grain boundaries are consisted of dislocations, they are used as models in order to characterize dislocation core structures. In this study, we fabricated several alumina (α-Al<SUB>2</SUB>O<SUB>3</SUB>) bicrystals with low-angle grain boundaries. The grain boundary structures were mainly observed by high-resolution transmission electron microscopy (HRTEM). It was found that the grain boundaries consisted of the array of discrete dislocations. They were not the perfect dislocations but the b=1/3<10-10> partial dislocations with stacking faults in between. Although the structures of the grain boundaries are depends on the orientation of two crystals, they can be explained by considering the misorientations, strain forces of the dislocations and excess energies of the stacking faults. Furthermore, we will demonstrate dopants segregations in the low-angle grain boundaries using the high-angle annular dark-field scanning TEM (HAADF-STEM) imaging.