Dawod Ibrahim, Patra Kajwal, Cardoch Sebastian, Jönsson H Olof, Sellberg Jonas A, Martin Andrew V, Binns Jack, Grånäs Oscar, Mancuso Adrian P, Caleman Carl, Timneanu Nicusor
Department of Physics and Astronomy, Uppsala University, Box 516, SE-751 20 Uppsala, Sweden.
European XFEL, Holzkoppel 4, DE-22869 Schenefeld, Germany.
ACS Phys Chem Au. 2024 May 8;4(4):385-392. doi: 10.1021/acsphyschemau.3c00072. eCollection 2024 Jul 24.
Water and ice are routinely studied with X-rays to reveal their diverse structures and anomalous properties. We employ a hybrid collisional-radiative/molecular-dynamics method to explore how femtosecond X-ray pulses interact with hexagonal ice. We find that ice makes a phase transition into a crystalline plasma where its initial structure is maintained up to tens of femtoseconds. The ultrafast melting process occurs anisotropically, where different geometric configurations of the structure melt on different time scales. The transient state and anisotropic melting of crystals can be captured by X-ray diffraction, which impacts any study of crystalline structures probed by femtosecond X-ray lasers.
水和冰常通过X射线进行研究，以揭示它们多样的结构和异常特性。我们采用一种碰撞辐射/分子动力学混合方法，来探究飞秒X射线脉冲与六方冰的相互作用方式。我们发现，冰会发生相变，形成一种晶体等离子体，其初始结构能保持数十飞秒。超快熔化过程呈现各向异性，结构的不同几何构型在不同时间尺度上熔化。晶体的瞬态和各向异性熔化可通过X射线衍射捕捉到，这会影响飞秒X射线激光探测晶体结构的任何研究。
