Non-thermal phase transitions in semiconductors under femtosecond XUV irradiation

Nikita A. Medvedev, Harald Olaf Jeschke, Beata Ziaja

Research output: Chapter in Book/Report/Conference proceedingConference contribution

6 Citations (Scopus)

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 languageEnglish
Title of host publicationDamage to VUV, EUV, and X-Ray Optics IV; and EUV and X-Ray Optics
Subtitle of host publicationSynergy Between Laboratory and Space III
DOIs
Publication statusPublished - Aug 1 2013
Externally publishedYes
EventDamage 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 2013Apr 18 2013

Publication series

NameProceedings of SPIE - The International Society for Optical Engineering
Volume8777
ISSN (Print)0277-786X
ISSN (Electronic)1996-756X

Other

OtherDamage to VUV, EUV, and X-Ray Optics IV; and EUV and X-Ray Optics: Synergy Between Laboratory and Space III
CountryCzech Republic
CityPrague
Period4/15/134/18/13

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

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  • Cite this

    Medvedev, N. A., Jeschke, H. O., & Ziaja, B. (2013). Non-thermal phase transitions in semiconductors under femtosecond XUV irradiation. In Damage to VUV, EUV, and X-Ray Optics IV; and EUV and X-Ray Optics: Synergy Between Laboratory and Space III [877709] (Proceedings of SPIE - The International Society for Optical Engineering; Vol. 8777). https://doi.org/10.1117/12.2019123