We report the lattice dynamics of transition metal thin films by using the ultrafast electron diffraction. We observe a suppression of the diffraction intensity in a few picosecond after the photoexcitation, which is directly interpreted as the lattice heating via the electron-phonon interaction. The electron-phonon coupling constants for Au, Cu and Mo are quantitatively evaluated by employing the two-temperature model, which are consistent with those obtained by optical pump-probe methods. The variation in the lattice dynamics of the transition metals are systematically explained by the strength of the electron-phonon coupling, arising from the elemental dependence of the electronic structure and atomic mass.
@article{arxiv.1601.04411,
title = {Direct observation of the lattice dynamics of transition metals using ultrafast electron diffraction},
author = {A. Nakamura and T. Shimojima and M. Nakano and Y. Iwasa and K. Ishizaka},
journal= {arXiv preprint arXiv:1601.04411},
year = {2016}
}