Description
Theory predicts that intense femtosecond laser pulses can induce ultrafast nonthermal transitions and melting in solid-state materials occurring on timescales of a few hundreds of femtoseconds [1]. During the first picosecond, the matter is in what is known as the warm dense matter (WDM) state — a state at the boundary between the solid phase and strongly coupled plasma. While the crystal lattice undergoes a rapid disordering, the density of the material stays almost unchanged. In lattices composed of multiple compounds, such as aluminium-III oxide and indium-III oxide, the decomposition dynamics of individual sublattices may vary. This can lead to the formation of a transient superionic state in which the metallic sublattice remains temporarily fixed in its original positions, while oxygen can move freely [2]. Here we present first results obtained during an interaction experiment carried out at the High Energy Density instrument (HED/European XFEL). Using a time-resolved X-ray diffraction technique, we observed ultrafast lattice dynamics in group-III oxides induced by intense X-ray laser pulses.
References:
[1] N. Medvedev, V. Tkachenko, V. Lipp, Z. Li, and B. Ziaja, Various damage mechanisms in carbon and silicon materials under femtosecond X-ray irradiation. 4Open 1, 3 (2018).
[2] R.A. Voronkov, N. Medvedev, A. E. Volkov, Superionic states formation in group III oxides irradiated with ultrafast lasers, Sci Rep 12, 5659 (2022).
