1206.1097 (R. Dronyak et al.)

Dynamics of colloidal crystals studied by pump-probe experiments at
FLASH    [PDF]

R. Dronyak, J. Gulden, O. M. Yefanov, A. Singer, T. Gorniak, T. Senkbeil, J. -M. Meijer, A. Al-Shemmary, J. Hallmann, D. D. Mai, T. Reusch, D. Dzhigaev, R. P. Kurta, U. Lorenz, A. V. Petukhov, S. Duesterer, R. Treusch, M. N. Strikhanov, E. Weckert, A. P. Mancuso, T. Salditt, A. Rosenhahn, I. A. Vartanyants

We present a time-resolved infrared (IR) pump and extreme-ultraviolet (XUV) probe diffraction experiment to investigate ultrafast structural dynamics in colloidal crystals with picosecond resolution. The experiment was performed at the FLASH facility at DESY with a fundamental wavelength of 8 nm. In our experiment, the temporal changes of Bragg peaks were analyzed and their frequency components were calculated using Fourier analysis. Periodic modulations in the colloidal crystal were localized at a frequency of about 4-5 GHz. Based on the Lamb theory, theoretical calculations of vibrations of the isotropic elastic polystyrene spheres of 400 nm in size reveal a 5.07 GHz eigenfrequency of the ground (breathing) mode.

View original: http://arxiv.org/abs/1206.1097