In-depth investigation of the effect of cooling rate on structural and dynamic properties of Cu54Hf46 alloy by molecular dynamics simulations

Abstract

The atomic structure, glass formation process and diffusion mechanism of the $C{u}_{54}H{f}_{46}$ alloy cooled with three different cooling rates have been investigated in depth by molecular dynamics simulations using the tight-binding potential. The partial pair distribution functions/total structure factors calculated at room temperatures are in good agreement with other/experimental data. A significant increase in the ⟨0,0,12,0⟩ ​​clusters has been observed in the 1551 bonded pairs due to the decreasing cooling rate. Most of the icosahedral-like clusters are Cu-centered clusters, indicating that Cu plays a critical role in the glass formation process. The decreasing cooling rate contributed to the development of the short/medium-range order. The diffusion fitting results have been shown that the mode-coupling theory and Vogel-Fulcher-Tammann equations are suitable to describe the change of diffusivity of Cu and Hf atoms in liquid alloy. The results showed that the decreasing cooling rate positively improved the glass formation process of the system.