Abstract
The atomic structures of crack walls due to cleavage fracture in silicon nitride (Si 3 N 4 ) and magnesium oxide (MgO) have been investigated by in situ straining transmission electron microscopy (TEM) and high-resolution electron microscopy (HREM) at room temperature. In the case of Si 3 N 4 , the crack walls on the (1 1̄ 0 0) plane were atomically flat, which indicates that the crack propagated along a particular crystal plane without deflection. On the other hand, the cleaved crack walls in MgO were not atomically flat but contained a number of square-shaped steps with a few {0 1 0} atomic layers in height. Thus, it can be said that the cleavage crack was deflected at the atomic level during its rapid propagation. The origin of their step structures is discussed using results from molecular dynamics (MD) simulations.
Original language | English |
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Pages (from-to) | 68-74 |
Number of pages | 7 |
Journal | Applied Surface Science |
Volume | 241 |
Issue number | 1-2 SPEC. ISS. |
DOIs | |
Publication status | Published - 2005 Feb 28 |
Externally published | Yes |
Keywords
- Cleavage fracture
- High-resolution electron microscopy
- In situ observation
- Magnesium oxide (MgO)
- Silicon nitride (Si N )
- Transmission electron microscopy
ASJC Scopus subject areas
- Chemistry(all)
- Condensed Matter Physics
- Physics and Astronomy(all)
- Surfaces and Interfaces
- Surfaces, Coatings and Films