Amorphous to crystalline phase transition in carbon induced by intense femtosecond x-ray free-electron laser pulses

TitleAmorphous to crystalline phase transition in carbon induced by intense femtosecond x-ray free-electron laser pulses
Publication TypeJournal Article
Year of Publication2012
AuthorsJ. Gaudin, O. Peyrusse, J. Chalupsky, M. Toufarova, L. Vysin, V. Hajkova, R. Sobierajski, T. Burian, D S. Farahani, A. Graf, M. Amati, L. Gregoratti, S.P Hau-Riege, G. Hoffmann, L. Juha, J. Krzywinski, R.A London, S. Moeller, H. Sinn, S. Schorb, M. Stormer, T. Tschentscher, V. Vorlicek, H. Vu, J. Bozek, C. Bostedt
JournalPhysical Review B
Volume86
Issue2
Pagination024103
Date PublishedJul
Type of ArticleArticle
ISBN Number1098-0121
KeywordsDIAMOND-LIKE CARBON, DYNAMICS, films, GRAPHITE, PLASMA, SPECTRA, SPECTROSCOPY
Abstract

We present the results of an experiment where amorphous carbon undergoes a phase transition induced by femtosecond 830 eV x-ray free-electron laser pulses. The phase transition threshold fluence is found to be 282 +/- 11 mJ/cm(2). Atomic force microscopy, photoelectron microscopy, and micro-Raman spectroscopy give experimental evidence for the phase transition in terms of a volume expansion, graphitization, and change of local order of the irradiated sample area. The interaction is modeled by an accurate time-dependent treatment of the ionization dynamics coupled to a two-temperature model. At the phase transition fluence threshold the free-electron density N-e is found to be at maximum 9 x 10(20) cm(-3) while the ion (atom) temperature is found to be 1050 K, e.g., above the crystallization activation temperature reported in the literature. This low ionization rate and high atom temperature suggest a thermally activated phase transition.

DOI10.1103/PhysRevB.86.024103
Division

nSI

Department

AXO

PID

a1b13ab48b7fbdd667268388ea834479

Alternate TitlePhys. Rev. B

Go back one page.