Abstract
The oxidation of an Al nanocluster with radius 100 Å placed in oxygen gas at room temperature is investigated by performing molecular dynamics simulations on parallel computers. The simulations take into account the effects of dynamic charge transfer between Al and O on the basis of electronegativity-equalization principles. We thereby find that molten surface oxides are saturated to depths of 28-33 Å; this saturation is accompanied by depletion of oxygen near the cluster in the environment. Upon quenching the cluster further in oxygen gas, amorphous surface oxides with depths are formed. The microscopic structures of the amorphous oxides are characterized.