Shoulder-peak formation in the process of quenching

The shoulder peak in liquid with medium range order (MRO) is first reported and its origin is analyzed by molecular dynamics calculation in this paper. Convincing evidence is presented that this structural order, manifested by a shoulder peak in the pair correlation function, can be interpreted as entanglement and interpenetration of ideal and defective icosahedra sharing common vertexes and faces. The bond energy which are directly related to chemical ordering, together with the geometrical constraint, play important roles in the local structure formation. It is concluded that liquid is able to sustain the presence of its predominantly icosahedral local order due to quick cooling. The present result thus indicated that shoulder peak induced medium range order should be a common feature of icosahedrally ordered liquids.