1999 Fiscal Year Final Research Report Summary
Formation of solid inclusion of inert gas atoms in bcc metals
| Project/Area Number |
10650658
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Physical properties of metals
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| Research Institution | The Institute of Physical and Chemical Research (RIKEN) |
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Principal Investigator |
YAGI Eiichi The Institute of Physical and Chemical Research (RIKEN), ミュオン科学研究室, 副主任研究員 (40087416)
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| Project Period (FY) |
1998 – 1999
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| Keywords | Fe / Xe / Solid inert gas bubbles / ion channeling method / ion implantation / イオン注入 |
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| Research Abstract |
It has been demonstrated that heavier inert gas atoms (Ar, Kr and Xe) implanted into metals at room temperature precipitate into a solid phase at high implantation doses. They are often referred as solid inert gas bubbles. In fcc metals they have an fcc structure which is crystallographically well alinged with matrices. The growth of such bubbles has been largely studied by transmission electron microscopy (TEM), whereas on their nucleation and formation processes there have been only a few studies, which are not observable by conventional TEM. The channeling method is very useful to such studies, because it provides information on lattice locations of implanted atom.
In the present study, in order to investigate the initial stage of Xe bubble formation in α-Fe (bcc), the lattice location of Xe atoms was studied by the channeling method for the Fe crystals implanted with Xe ions at 150 keV at room temperature up to doses 10ィイD114ィエD1, 4x10ィイD114ィエD1, 10ィイD115ィエD1 and 10ィイD116ィエD1Xe/cmィイ
… More
D12ィエD1. Most of the Xe atoms are located at substitutional (S) and random (R) sites. At low implantation doses small portion of them are additionally located at tetrahedral (T) sites and the sites slightly displaced from a lattice point by about 0.085 nm in the <111> direction (D site). The T- and D-site occupancies are considered to be a result of the formation of Xe-vacancy (V) complexes, XeVィイD24ィエD2 and XeV, respectively, due to a strong interaction between the Xe atoms and the vacancies introduced during implantation. The R-site occupancy is ascribed to the Xe atoms associated with a larger number of vacancies. With increasing implantation dose the fraction of S-, D- and T-site occupancies decrease, whereas that of the R-site occupancy increases. It is concluded that at the initial stage of implantation the Xe-vacancy complexes i.e., XeV, XeVィイD24ィエD2 and larger ones, are formed and they act as nucleation centers for subsequent growth to Xe bubbles. For the migration of Xe atoms, which is required in the process of the Xe bubble formation, the migration mechanism of Xe atoms in the form of XeVィイD23ィエD2 complex is proposed. Less
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Research Products
(2 results)
