The electron-excitation induced bond strength variations in metals have been predicted from density-functional theory calculations and observed experimentally, while the microscopic mechanism has yet to be elucidated. Here, we present a minimal model that reproduces the phonon hardening and softening for fcc- and bcc-structured metals as a result of the electron thermal excitation. We explain why the phonon mode softens at the N point for bcc-structured metals.
Categories: cond-mat.mtrl-sci