Molecular dynamics study of special quasirandom structure of Zr-Nb alloys

Irradiation damage to zirconium alloys (e.g., niobium (Zr-Nb) alloy) is the key design of fission-reactor structural materials and fuel rod cladding materials. Atomic scale computational simulations such as molecular dynamics first principles are often needed understand physical mechanism irradiation damage. For simulation randomly substitutional solid solution, it necessary construct large-sized supercells that can reflect random distribution characteristics alloy elements. However, not suitable use large-size (such ≥ 200 atoms) for principle calculation, due large cost. Special quasirandom (SQS) usually used calculation. The SQS partly elements, but only corresponds one configuration specific components, hence whether this model statistical average multiple local configurations in a real solution still an open question, needs further studying verifying. Molecular (MD) be carried out on with larger based substitution (RSS) method, these include more configurations. Therefore, MD studies Zr-Nb RSS SQS-extended supercells. critical size supercell which truly properties determined. Then lattice constant, formation energy energy-volume relationship series calculated compared. results show constants, volume curves obtained by close corresponding values supercells, so study alloys.