  The annealing treatment in the advanced manufacturing process, e.g.,
laser-assisted manufacturing, determines the final state of glasses which is
critical to its thermal, electrical and mechanical properties. Energy barriers
analysis based on the potential energy surface offers an effective way to study
the microscopic evolution of the inherent structures during the annealing
process in a broadening timescale range, i.e., from atomistic timescale ( ~ ps)
to experimental timescale (~ s). Here, we find the distribution activation
energy barriers in the potential energy surface can be divided into three
regimes 1, the distribution mainly follows the Rayleigh distribution when the
annealing rate Rdot < 1e15 K/s; 2, two different modes, i.e., an exponentially
decaying mode and a Rayleigh distribution mode, are found in the spectra when
the annealing rate 1e15 K/s < Rdot < instant; 3, the spectra is almost
following the exponentially decaying mode when the system is under the instant
annealing process. However, the spectra of relaxation energy barriers only show
an exponentially decaying mode with a decreasing decay parameter. A multi
timescale model for any specific annealing rate, which is beyond the limit of
the conventional atomistic simulations, i.e., molecular dynamics simulations,
is then proposed based on the distribution of the energy barriers. Such a model
enables quantitative explanations and predictions of the heat release during
the annealing process of the nanocalorimetry measurements or laser-assisted
manufacturing.
