Ultrafast dynamics of thermal and nonthermal structural changes in metals

Although structural phase changes in metals are a vital problem due to its fundamental importance as well as wide applicability in materials processing and manufacturing, the underlying physics of this process is still not fully understood and remains only at a phenomenological level. The study of the dynamics associated with structural changes only becomes possible recently with advances of femtosecond laser techniques. In this paper, we discuss our experimental results in the ultrafast dynamics of structural changes in metals induced by both thermal and nonthermal processes by monitoring materials states through their transient dielectric constants. These results lead to a more complete understanding of the physical mechanism of structural phase changes in metals.