Molecular dynamics study of icosahedral ordering and defect in the Ni3Al liquid and glasses

The amorphous transition in Ni3Al system is investigated in detail at a temperature from 2000 K down to 300 K with F–S potential by MD simulation. The pair correlation functions and the pair analysis technique are used to study the cluster evolution in liquid and glass. In addition to a structural change, a dramatic split of second peak of g(r) is in association with the glass transition. Especially, the number of the type of defective icosahedron defined by eight 1551 bonds, two 1661 bonds, and two 1441 bonds is much greater than the number of various Frank and Bernal polyhedra.