Abstract
A detailed field-ion microscope (FIM) study has been made of the vacancy structure of a (220) platelet created by a single 30 keV W+ ion in a platinum-4·0 at. % gold alloy; the specimen was maintained at 40 K (below substage IIB) during the in situ irradiation at ∼ 2 × 10−9 torr. Prior to the pulsed field-evaporation dissection of the specimen at 40 K it was warmed isochronally to 100 K (above substage IIC). The (220) platelet was found to consist of 31 vacant lattice sites, lying in four (220) planes, and clustered in a disc-shaped region which is ∼ 20 Å in diameter. If only first nearest-neighbour lattice sites are considered, then the distribution of cluster sizes is as follows: (1) two monovacancies, and (2) one jumbo vacancy cluster containing 29 vacancies. The range of the vacancy concentration within the (220) vacancy platelet is ∼35 to 44 at. %. Employing the modified Kinchin-Pease equation it was calculated that the displacement efficiency (k) for this platelet is 0·12. It is suggested that the prismatic dislocation loops lying on {220}-type planes, observed by transmission electron microscopy, in ion or fast-neutron irradiated platinum can form as a result of the direct collapse of {220}-type vacancy platelets.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 257-272 |
| Number of pages | 16 |
| Journal | Philosophical Magazine A: Physics of Condensed Matter, Structure, Defects and Mechanical Properties |
| Volume | 37 |
| Issue number | 2 |
| DOIs | |
| State | Published - Feb 1978 |
Funding
f This work was supported by the U.S. Department of Energy. Additional support was received from the National Science Foundation through the use of the technical facilities of the Materials Science Center at Cornell University.
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- General Materials Science
- Condensed Matter Physics
- Physics and Astronomy (miscellaneous)
- Metals and Alloys