Abstract
When a semiconductor or a dielectric is irradiated with ultrashort intense X-ray pulse, several processes occur: first the photoabsorption brings the electron subsystem out of equilibrium, bringing valence or deeper shells electrons into high energy states of the conduction band. Then, secondary electron cascading promotes further electrons of the valence to conduction band increasing their number there. These electrons also influence the atomic motion, modifying the interatomic forces. This process is known as a nonthermal melting. It can turn a material into a new phase state on ultrashort timescales. Recently developed hybrid model for treating all of these processes with different computational tools was reported in [N. Medvedev et al, New J. Phys. 15, 015016 (2013)]. Based on this model, we present here further investigations of nonthermal processes occurring in diamond under irradiation with a FLASH pulse of 10 fs FWHM and 92 eV photon energy. It is shown that the diamond turns into graphite under such irradiation, independently whether constant pressure or constant volume modeling is performed. However, for the latter case, the time of the nonthermal phase transition is longer (few tens of fs for P=const vs few hundreds of fs for V=const) and the damage threshold is slightly higher (0.69 eV/atom vs 0.74 eV/atom, correspondingly).
| Original language | English |
|---|---|
| Title of host publication | Damage to VUV, EUV, and X-Ray Optics IV; and EUV and X-Ray Optics |
| Subtitle of host publication | Synergy Between Laboratory and Space III |
| Volume | 8777 |
| DOIs | |
| Publication status | Published - 2013 |
| Externally published | Yes |
| Event | Damage to VUV, EUV, and X-Ray Optics IV; and EUV and X-Ray Optics: Synergy Between Laboratory and Space III - Prague, Czech Republic Duration: Apr 15 2013 → Apr 18 2013 |
Other
| Other | Damage to VUV, EUV, and X-Ray Optics IV; and EUV and X-Ray Optics: Synergy Between Laboratory and Space III |
|---|---|
| Country | Czech Republic |
| City | Prague |
| Period | 4/15/13 → 4/18/13 |
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Keywords
- Free-Electron Laser FLASH
- Graphitization of diamond
- Nonthermal melting
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Computer Science Applications
- Applied Mathematics
- Electrical and Electronic Engineering
Cite this
Non-thermal phase transitions in semiconductors under femtosecond XUV irradiation. / Medvedev, Nikita A.; Jeschke, Harald Olaf; Ziaja, Beata.
Damage to VUV, EUV, and X-Ray Optics IV; and EUV and X-Ray Optics: Synergy Between Laboratory and Space III. Vol. 8777 2013. 877709.Research output: Chapter in Book/Report/Conference proceeding › Conference contribution
}
TY - GEN
T1 - Non-thermal phase transitions in semiconductors under femtosecond XUV irradiation
AU - Medvedev, Nikita A.
AU - Jeschke, Harald Olaf
AU - Ziaja, Beata
PY - 2013
Y1 - 2013
N2 - When a semiconductor or a dielectric is irradiated with ultrashort intense X-ray pulse, several processes occur: first the photoabsorption brings the electron subsystem out of equilibrium, bringing valence or deeper shells electrons into high energy states of the conduction band. Then, secondary electron cascading promotes further electrons of the valence to conduction band increasing their number there. These electrons also influence the atomic motion, modifying the interatomic forces. This process is known as a nonthermal melting. It can turn a material into a new phase state on ultrashort timescales. Recently developed hybrid model for treating all of these processes with different computational tools was reported in [N. Medvedev et al, New J. Phys. 15, 015016 (2013)]. Based on this model, we present here further investigations of nonthermal processes occurring in diamond under irradiation with a FLASH pulse of 10 fs FWHM and 92 eV photon energy. It is shown that the diamond turns into graphite under such irradiation, independently whether constant pressure or constant volume modeling is performed. However, for the latter case, the time of the nonthermal phase transition is longer (few tens of fs for P=const vs few hundreds of fs for V=const) and the damage threshold is slightly higher (0.69 eV/atom vs 0.74 eV/atom, correspondingly).
AB - When a semiconductor or a dielectric is irradiated with ultrashort intense X-ray pulse, several processes occur: first the photoabsorption brings the electron subsystem out of equilibrium, bringing valence or deeper shells electrons into high energy states of the conduction band. Then, secondary electron cascading promotes further electrons of the valence to conduction band increasing their number there. These electrons also influence the atomic motion, modifying the interatomic forces. This process is known as a nonthermal melting. It can turn a material into a new phase state on ultrashort timescales. Recently developed hybrid model for treating all of these processes with different computational tools was reported in [N. Medvedev et al, New J. Phys. 15, 015016 (2013)]. Based on this model, we present here further investigations of nonthermal processes occurring in diamond under irradiation with a FLASH pulse of 10 fs FWHM and 92 eV photon energy. It is shown that the diamond turns into graphite under such irradiation, independently whether constant pressure or constant volume modeling is performed. However, for the latter case, the time of the nonthermal phase transition is longer (few tens of fs for P=const vs few hundreds of fs for V=const) and the damage threshold is slightly higher (0.69 eV/atom vs 0.74 eV/atom, correspondingly).
KW - Free-Electron Laser FLASH
KW - Graphitization of diamond
KW - Nonthermal melting
UR - http://www.scopus.com/inward/record.url?scp=84880754195&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84880754195&partnerID=8YFLogxK
U2 - 10.1117/12.2019123
DO - 10.1117/12.2019123
M3 - Conference contribution
AN - SCOPUS:84880754195
SN - 9780819495792
VL - 8777
BT - Damage to VUV, EUV, and X-Ray Optics IV; and EUV and X-Ray Optics
ER -