Glass Formation in Binary Alloys Studied Through Combinatorial Sputtering

Glass formation is a complex phenomenon including thermodynamic and kinetic aspects that are often controlled by extrinsic contributions. While bulk metallic glasses are typically fabricated through multicomponent alloys, binary alloys offer a simpler alternative for studying glass formation. In this study, we fabricated 57 binary alloy systems through combinatorial sputtering, with 66 alloys per alloy system. We developed an automated analysis to determine structure and composition through x-ray diffraction and energy-dispersive x-ray spectroscopy respectively. We found that 17% of the alloys form glasses under a cooling rate of ~10⁸ K/s. Interestingly, commonly used factors like size ratio, heat of mixing, and full-width-half-maximum of a diffraction peak are ineffective in predicting glass formation. However, crystal structure mismatch of the alloys’ elements emerged as the strongest indicator of glass formation under sputtering conditions of binary alloys. The differences in glass formation under slow cooling rates used for bulk glass formation and the here observed glass formation under rapid cooling rates is discussed.