Journal of Applied Physics
Femtosecond, 8.04 keV x-ray pulses are used to probe the lattice dynamics of a 150 nm Cu (111) single crystal on a mica substrate irradiated with 400 nm, 100 fs laser pulses. For pump fluences below the damage and melting thresholds, we observed lattice contraction due to the formation of a blast force and coherent acoustic phonons with a period of ∼69 ps. At larger pump fluence, solid to liquid phase transition, annealing, and recrystallization were measured in real time by monitoring the intensity evolution of the probing fs x-ray rocking curves, which agreed well with theoretical simulation results. The experimental data suggest that the melting process is a purely thermal phase transition. This study provides, in real time, an ultrafast time-resolved detailed description of the significant processes that occur as a result of the interaction of a femtosecond light-pulse with the Cu (111) crystal surface. Published by AIP Publishing. [http://dx.doi.org/10.1063/1.4975198]
Original Publication Citation
Li, R., Ashour, O. A., Chen, J., Elsayed-Ali, H. E., & Rentzepis, P. M. (2017). Femtosecond laser induced structural dynamics and melting of cu (111) single crystal. An ultrafast time-resolved x-ray diffraction study. Journal of Applied Physics, 121(5), 055102. doi:10.1063/1.4975198
Li, Runze; Ashour, Omar A.; Chen, Jie; Elsayed-Ali, H. E.; and Rentzepis, Peter M., "Femtosecond Laser Induced Structural Dynamics and Melting of Cu (111) Single Crystal. An Ultrafast Time-Resolved X-Ray Diffraction Study" (2017). Electrical & Computer Engineering Faculty Publications. 129.