The Effect Of Atom Mismatch On Structure And Dynamical Properties Of Liquid Metal

In this paper, we investigate the effect of atom mismatch on structure anddynamical properties of liquid metal by molecular dynamics simulations, and discuss itsinfluence on glass forming ability (GFA).Firstly, we investigate the relationship between atom mismatch and its glassforming ability of liquid Cu. We found that the order degree of the system increases andatom tends to be short-range order with the increase of atom-size mismatch. Meanwhile,the bonding ability of unlike-atoms strengthens and the bonding probability incerases.Then the effect of atom-size mismatch on glass-forming ability is analyzed in terms offree volume, and the results show that free volume decreases, atoms move slowly andthe structural rearrangement ability of atoms decreases which contribute to form glass,with the increase of atom-size mismatch in the system.Three liquid alloy systems with different relative content of atoms and sameatom-size mismatch are analyze and compared with each other to study the effect ofatom mismatch on structure and dynamical properties of liquid metal. We find that thefirst atom layer changes with temperature and atom mismatch. With the increasing atommismatch, Icosahedral and defect icosahedral structures are both increase at first anddecrease finally, the fcc and hcp structures decrease, and the bcc structures increaseobviously. It means that the bcc structures play an important role in the system whichhas larger atom mismatch.In addition, the decreasing atom mismatch of liquid alloy leadto large free volume, less random close-packed structures and fast atomic motion.Conversely, when the atom mismatch of liquid alloy increase, free volume will be small,the random close-packed structures get more, which prevent the movement of atomsand the diffusion ability gets weak.