Origin of enhanced glass-forming ability of Ce-containing Al-Fe alloy: Ab initio molecular dynamics study

Using ab initio molecular dynamics simulation, glass-forming abilities of Al₉₀Fe₁₀ and Al₉₀Fe₅Ce₅ alloys have been investigated successfully correlated with the atomic structure and composition. The origin of enhanced glass-forming ability for Al ₉₀Fe₅Ce₅ alloy is interpreted by taking advantage of the calculated information. It is found that the enhanced glass-forming ability with the addition of Ce into Al₉₀Fe ₁₀ alloy, in contrast to the transitional metallic glass, has nothing to do with the kinetic factor and stability of local atomic packing, but the atomic environment and medium-range order in the supercooled liquid state. A comparison of structure and composition between the supercooled liquid and potential crystalline phases demonstrates that the precipitation of the solid solution and compounds from the amorphous matrix for Al₉₀Fe ₁₀ alloy becomes much more difficult with the addition of Ce. After glass transition, the resultant glassy state for Al₉₀Fe ₅Ce₅ alloy is further stabilized by stable local atomic packings.