Micro-alloying effects of Co on structural and dynamic properties of CeAlCu glass-forming melts by ab initio molecular dynamics simulations

Abstract The structural and dynamic properties of Ce70-xAl10Cu20Cox (x = 0, 0.5, 1, 2 and 5) glass-forming melts were investigated by ab initio molecular dynamics simulations. We found that Al or Cu atoms were dispersed homogeneously with minor Co addition. The bond orientational order parameter W ^ 6 of Al decreased with Co addition, which agreed well with the experimental result. The short-range order was regulated with minor Co addition, which benefited the glass-forming ability. Strong hybridizations between Co 3d and Al 3p and Co 3d and Ce 5d were observed. The hybridizations are the physical origin of the bond-shortening effects and they contribute to the special atomic packing. We investigated the dynamic properties of the melts and found that the self-diffusion coefficient of Cu reached a minimum in the Ce69Al10Cu20Co1 melt. The investigation of Ce70-xAl10Cu20Cox glass-forming melts provide an improved understanding of the micro-alloying effects of Co at the atomic scale.