2011/11/09 by J. Gaudin, Gaudin, J., J. Chalupský +61
Engineering · Materials Science · Physics and Astronomy · #Diamond and Carbon-based Materials Research #FOS: Physical sciences #Integrated Circuits and Semiconductor Failure Analysis #Ion-surface interactions and analysis #Materials Science (cond-mat.mtrl-sci) #Mesoscale and Nanoscale Physics (cond-mat.mes-hall) #cond-mat.mes-hall #cond-mat.mtrl-sci
paper · pdf · doi:10.48550/arxiv.1111.2134
arxiv created 2011/11/09 · openalex publication_date 2011/11/09 · arxiv updated 2011/11/10 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We present the results of an experiment where amorphous carbon was irradiated by femtosecond x-ray free electron laser pulses. The 830 eV laser pulses induce a phase transition in the material which is characterized ex-situ. The phase transition energy threshold is determined by measuring the surface of each irradiated area using an optical Nomarski microscope. The threshold fluence is found to be 282 +/- 11 mJ/cm2, corresponding to an absorbed dose at the surface of 131 +/-5 meV/atom. Atomic force microscopy measurements show volume expansion of the irradiated sample area, suggesting a solid to solid phase transition. Deeper insight into the phase transition is gained by using scanning photoelectron microscopy and micro-Raman spectroscopy. Photoelectron microscopy shows graphitization, i.e. modification from sp3 to sp2 hybridization, of the irradiated material. The micro-Raman spectra show the appearance of local order, i.e. formation of graphite nanocrystals. Finally, the nature of the phase transition is discussed, taking into account previous theory and experimental results.