Abstract Scope |
The α-relaxation time determined by scattering experiments and simulation as the decay rate of the first peak of the structure function, S(Q), τ(Qmax), is commonly interpreted as the structural relaxation time which represents the collective atomic dynamics, but we usually overlook its origin. Here we investigate the origin of the α-relaxation time through the examination of the Van Hove correlation function in real space. We show that the α-relaxation time reflects all dynamics from the short-rang order (SRO) and the medium-range order (MRO), although the disparate natures of the SRO and the MRO are clearly seen in the dynamic correlations of atoms. This investigation leads to more rigorous interpretation of the α-relaxation time determined by scattering experiments. |