Ultrafast Structural Dynamics in InSb Probed by Time-Resolved X-Ray Diffraction

Ultrafast structural dynamics in laser-perturbed InSb are studied using time-resolved x-ray diffraction with a novel femtosecond x-ray source. We report the first observation of a delay in the onset of lattice expansion, which we attribute to energy relaxation processes and lattice strain propagation. In addition, we observe direct indications of ultrafast disordering on a subpicosecond time scale. {copyright} {ital 1999} {ital The American Physical Society }