Femtosecond phase-transition in hard x-ray excited bismuth

0505015 - FZÚ 2020 RIV GB eng J - Journal Article
Makita, M. - Vartiainen, I. - Mohacsi, I. - Caleman, C. - Diaz, A. - Jonsson, H.O. - Juranic, P. - Medvedev, Nikita - Meents, A. - Mozzanica, A. - Opara, N.L. - Padeste, C. - Panneels, V. - Saxena, V. - Sikorski, M. - Song, S. - Vera, L. - Willmott, P. R. - Beaud, P. - Milne, C. J. - Ziaja-Motyka, B. - David, C.
Femtosecond phase-transition in hard x-ray excited bismuth.
Scientific Reports. Roč. 9, Jan (2019), s. 1-7, č. článku 602. ISSN 2045-2322. E-ISSN 2045-2322
EU Projects: European Commission(XE) 654148 - LASERLAB-EUROPE
Institutional support: RVO:68378271
Keywords : hard x-ray excitation in bismuth single crystal * femtsosecond phase-transition * electron-ion equilibration process
OECD category: Optics (including laser optics and quantum optics)
Impact factor: 3.998, year: 2019
Method of publishing: Open access

The evolution of bismuth crystal structure upon excitation of its A1g phonon has been intensely studied with short pulse optical lasers. Here we present the first-time observation of a hard x-ray induced ultrafast phase transition in a bismuth single crystal at high intensities (~1014 W/cm2). The lattice evolution was followed using a recently demonstrated x-ray single-shot probing setup. The time evolution of the (111) Bragg peak intensity showed strong dependence on the excitation fluence. After exposure to a sufficiently intense x-ray pulse, the peak intensity dropped to zero within 300 fs, i.e. faster than one oscillation period of the A1g mode at room temperature. Our analysis indicates a nonthermal origin of a lattice disordering process, and excludes interpretations based on electron-ion equilibration process, or on thermodynamic heating process leading to plasma formation.
Permanent Link: http://hdl.handle.net/11104/0296542