Abstract
Lattice defects in a ferroelectric material strongly affect its physical properties. However, there are fewer studies on plane and line defects, which are important lattice defects. In the present study, LiNbO_3 bicrystals with low-angle tilt grain boundaries were successfully fabricated by diffusion bonding. Here, LiNbO_3 is a widely used ferroelectric material with pyroelectric, piezoelectric, electro-optic and photoelastic properties, and a high Curie point. The resultant boundary was then investigated using conventional TEM and high-resolution TEM, and it was found that a boundary dislocation dissociated into two or three partial dislocations with a narrow separation distance. A crystallographic consideration with the TEM observations suggests the Burgers vectors of the partial dislocations and structures of stacking fault.
