[Download]Name: Hu Y C, Guan P F, Wang Q, et al. Pressure effects on structure and dynamics of metallic glass-forming liquid[J]. The Journal of Chemical Physics, 2017, 146(2): 024507.

Class: 2017

Content:
Although the structure and dynamics of metallic glass-forming liquids have been extensively investigated,
studies of the pressure effects are rare. In the present study, the structural and dynamical
properties of a ternary metallic liquid are systematically studied via extensive molecular dynamics
simulations. Our results clearly show that, like isobaric cooling, isothermal compression could also
slow down the dynamics of metallic liquid, leading to glass formation. However, the temperatureand
pressure-induced glass transitions differ in the formation of local coordination structures and the
variation of fragility. The increase of the kinetic fragility with increasing pressure is also accompanied
by a monotonic structural fragility change. These findings may suggest a link between dynamics
and structure. In addition, with increasing pressure, the dynamics becomes more heterogeneous, as
revealed by the non-Gaussian parameter and dynamic correlation length. Here the length scales of
both slow and fast domains are examined and discussed by analyzing the four-point dynamic structure
factor associated with spatial correlations of atomic mobility. These correlation lengths coexist in the
metallic liquids and grow comparatively in the considered temperature and pressure ranges. Finally,
the scaling relation between the relaxation times and correlation lengths is discussed, which is found
to be consistent with the spirit of Adam-Gibbs and random first-order transition theories.