Structural investigation upon the high glass-forming ability in Fe-doped ZrCuAl multicomponent alloys

Understanding the underlying mechanism of microalloying affecting the glass formation in multicomponent alloys is scientifically required, while addressing this issue remains a challenge. In this work, the structural mechanisms of extraordinarily high glass-forming ability (GFA) caused by Fe doping in ZrCuAl bulk metallic glasses was investigated via synchrotron radiation techniques combined with simulations. It is revealed that when minor Fe (5 at.%) are doped, the local structures (clusters) have relatively high values of some structural parameters, in terms of fivefold symmetry, geometrical regularity, atomic packing, and chemical interaction between heterogeneous atoms. The combination of these structural factors leads to stabilized amorphous structure and enhanced GFA. This work may extend our understanding on the sensitive dependence of GFA on the concentration of doping atoms in multicomponent metallic glasses.