Femtosecond electron diffraction: an atomic perspective of condensed phase dynamics

Femtosecond electron diffraction (FED) is a new technique within the still-developing field of ultrafast diffraction. This paper presents an outline of the basic features of FED, including a brief history of its development in terms of the technical challenges of working with femtosecond electron pulses and the ultrathin samples required. Application of FED to melting in aluminium and gold excited by intense femtosecond laser pulses will be discussed. The interplay of experiment and theory will be explored, particularly with respect to molecular dynamics simulations of the same processes we experimentally observe. Homogeneous nucleation emerges as an important melting mechanism under the strongly-driving conditions that we employ. Future applications of FED will be discussed in terms of progress to date.