Small-angle pump–probe studies of photoexcited nanoparticles
Nonequilibrium femtosecond laser excitation can lead to very fast structural dynamics in nanoparticle suspensions. The mesoscopic scale of vapor bubble formation and particle ablation has been resolved by pulsed X-ray scattering at the time-resolved beamline at ESRF. The threshold process of bubble formation reveals the explosive boiling of the superheated water layer. A projection to future free-electron laser capabilities makes single-shot, single-particle probing at high resolution realistic.
A. Plech, V. Kotaidis, K. Istomin and M. Wulff
![[SAXS pattern]](https://www.iucr.org/__data/assets/image/0014/4118/240JSR.tif.gif)
Time-resolved SAXS pattern of laser-excited gold nanoparticles showing the formation of nanobubbles on the subnanosecond scale. The difference between excited and nonexcited states is plotted in false colors (yellow/white: intensity increase, black: intensity decrease).
