Abstract
Observations of a large number of different oxides in the electron microscope clearly indicate that a crucial role is played by the presence or absence of encapsulating layers, either amorphous carbon, graphitic carbon or damaged metallic regions produced by DIET of the oxygen, and point defect diffusion in the subsurface region. In the presence of an encapsulation layer DIET slows by a factor which is related to the point defect migration through this layer.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 253-257 |
| Number of pages | 5 |
| Journal | Ultramicroscopy |
| Volume | 25 |
| Issue number | 3 |
| DOIs | |
| State | Published - 1988 |
Funding
ergy required to break its bonds (assuming that it is knocked away from the surface), which is far less. In the case of electronic transition processes, bulk radio1ysis is the analog of bulk ballistic damage, and DIET the analog of surface sputtering. When there is an encapsulation layer we can only lose oxygen by radiolysis, and since this requires far more kinetic energy for the atom it will be a far slower process whereas without the layer the faster DIET takes place. If the encapsulation layer allows sufficient point defect migration, then atoms can diffuse to the surface and then DIET, so that the damage is not arrested by the layer. Conclusions: The presence of encapsulation layers plays a crucial role in DIET from oxides within the electron microscope, as does diffusion This work was funded by the Air Force Office of Scientific Research on grant number AFOSR 86-0344 DEF.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics
- Instrumentation