Publication Date:
2018
Description:
Ceramic bicrystal formation using spark plasma sintering, and subsequent grain boundary analysis by scanning transmission electron microscopy techniques.
Abstract
A SrTiO3 bicrystal with a low‐angle twist grain boundary was fabricated using the spark plasma sintering (SPS) instrument. The atomic and electronic structure of the grain‐boundary core was characterized using scanning transmission electron microscopy techniques. It was determined that the boundary is comprised of 2 types of defects with distinct electronic structures: screw dislocations and dislocations with an [001] edge component. The dislocations with an [001] edge component dissociated into 2 partial dislocations, separated by a stacking fault consisting of 2 Ti–O layers. The screw dislocations are attributed to the twist component of the grain boundary, while dislocations with an [001] edge component are attributed to surface steps on the original (100) SrTiO3 surfaces prior to diffusion bonding. The observed repeat distances between the dislocations with edge components along the grain‐boundary plane are smaller than those discovered during traditional diffusion bonding experiments. The higher planar defect density observed in this study results partly from higher heating rates, lower processing temperatures, and shorter holding times during SPS processing.
Print ISSN:
0002-7820
Electronic ISSN:
1551-2916
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
,
Physics
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