Electronegativity difference as a factor for evaluating the thermal stability of Al-rich metallic glasses

This article proposes a factor, the critical electronegativity difference Δx cri, to correlate alloy composition with thermal stability and glass-forming ability of Al–Ni–RE (RE: Rare Earth element) ternary metallic glasses. The Al-rich metallic glasses with Δx > Δx cri exhibit glassy behavior, whereas alloys with Δx < Δx cri are nanocrystalline. Nanoglassy alloys occur when Δx ≈ Δx cri. The best glass formers are located near Δx cri. Furthermore, an equation has been deduced to calculate Δx cri with varying RE covalent atomic radius.