Tuning of tetrahedrality in a silicon potential yields a series of monatomic (metal-like) glass formers of very high fragility.
We obtain monatomic glass formers in simulations by modifying the tetrahedral character in a silicon potential to explore a triple point zone between potentials favoring diamond (dc) and bcc crystals. dc crystallization is always preceded by a polyamorphic transformation of the liquid, and is frustrated when the Kauzmann temperature of the high temperature liquid intersects the liquid-liquid coexistence line. The glass forming liquids are extraordinarily fragile. Our results suggest that Si and Ge liquids may be vitrified at a pressure close to the diamond-beta-tin-liquid triple point.
Molinero
Valeria
V
Department of Chemistry and Biochemistry, Arizona State University, Tempe, Arizona 85287, USA. valeria.molinero@utah.edu
Sastry
Srikanth
S
Angell
C Austen
CA