| Project/Area Number |
09640399
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
固体物性Ⅰ(光物性・半導体・誘電体)
|
|---|
| Research Institution | Yamaguchi University |
|---|
Principal Investigator |
SHIMAMURA Shuji Yamaguchi University, Faculty of Engineering, Professor, 工学部, 教授 (40144919)
|
|---|
| Project Period (FY) |
1997 – 1998
|
| Project Status |
Completed (Fiscal Year 1998)
|
| Budget Amount *help |
¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1998: ¥200,000 (Direct Cost: ¥200,000)
Fiscal Year 1997: ¥600,000 (Direct Cost: ¥600,000)
|
|---|
| Keywords | fracture / deformation / electronic structure |
|---|
| Research Abstract |
In this project, excitation of electrons and atoms by deformation and fracture in solids has been investigated theoretically as a fundamental study of the mechanism of electron and atom emission caused by fracture in semiconductors.
The following studies have been made : (1) the mechanism of fracture- induced electron emission (2) computer simulations of atomic motions during crack extension ; (3) the electronic response to lattice displacement.
The results are summarized as follows
(1) The number of emitted electrons and the energy distribution of emitted electrons in fractured metals, and the increase of the electrical conductivity in fractured semiconductors have been calculated in terms of thermoelectronic emission. It has been shown that electrons near fracture surfaces are in the excited states corresponding to about 1,000 K.
(2) Computer simulations of atomic motions caused by fracture under tensile strain have been carried out using the two- dimensional model system. It has been shown that there is a critical value of tensile strain above which the number of emitted atoms increases rapidly. This result reproduces fractoemission observed in brittle solids such as semiconductors and insulators.
(3) The electronic response to lattice displacement in Pd and Ag has been studied by means of electronic structure calculations. It has been shown that lattice displacement increases the electron energy of Pd relative to that of Ag. An electronic origin of hydrogen embrittlement in Pd has been proposed on the basis of the calculated results.
|
