金属玻璃结构及其失稳的原子层次研究

管鹏飞, 孙胜君

Atomic-Level Study in the Structure and Its Instability of Metallic Glasses

GUAN Pengfei, SUN Shengjun

图4 受限条件下金属玻璃过冷液体的短程序与结构弛豫出现退耦合关联：受限的金属玻璃模型，原子构型中二十面体比重及结构弛豫特征随温度和受限度的变化规律，与受限度密切相关的结构短程序-弛豫特性之间的关联^[55]
(a) schematic configuration of the sandwich-pinning geometry
(b) the fraction of full icosahedra <0,0,12,0> as a function of z at different temperatures (z—the distance of an atom from the closer wall)
(c) temperature dependence of

τ_{α, ? z}

for Cu₅₀Zr₅₀ confined between two rough walls, the structural relaxation time

τ_{α}

of the bulk is also included in dashed rectangular for comparison. The sharp contrast with Fig.4b demonstrates the decoupling between slow dynamics and full icosahedra (

τ_{α, ? z}

—z-dependent relaxation time)
(d) the contour map of the relaxation times in confinement

τ_{α, ? z}

as a 2D function of

f_{i c o}

and z. It is obvious that

τ_{α, ? z}

can change remarkably when

f_{i c o}

is invariant

Fig.4 Decoupling between the local clusters and the structural relaxation in confined metallic glass forming liquids^[55]