Photoinduced ultrafast structural dynamics of nanomaterials

We will report our study of photoinduced structural dynamics of nanomaterials of various shapes and sizes by a femtosecond laser heating pulse as detected by time-resolved electron diffraction or transient optical absorption. This work improves the understanding of nanoscale heat transfer and the ultrafast structural dynamics in nanomaterials such as thin films, spheres, prisms, discs, rods, pyramids and cubes. This work allows us to elucidate the roles of dynamic expansion/contraction and the more well-known static linear expansion. Both mechanisms play an important but different role in the observed structural changes at a different time scale. We will present comparative analysis of the experimental measurements for various samples as obtained by our own group and those reported by others.