Observation of ultrafast lattice heating using time resolved electron diffraction

We use ultrafast electron diffraction to study lattice heating of 20 nm noble metal films after femtosecond optical excitation with moderate excitation fluences. Using the Debye-Waller effect, the rise times of the lattice temperature were measured to be 1.1 ps in copper (5.9 mJ/cm(2) incident fluence) and 4.7 ps in gold (0.9 mJ/cm(2)).