Crystal Phases of Glass-Forming Mixtures

Abstract

We compare the potential energy at zero temperature of a range of crystal structures for a glass-forming binary mixture of Lennard-Jones particles. The lowest energy ordered state consists of coexisting phases of a single component face centered cubic structure and an equimolar cesium chloride structure. An infinite number of layered crystal structures are identified with energies close to this groundstate. We demonstrate that the finite size increase of the energy of the coexisting crystal with incoherent interfaces is sufficient to destabilize this ordered phase in simulations of typical size. Specific local coordination structures are identified as of possible structural significance in the amorphous state. We observe rapid crystal growth in mixtures near the equimolar composition.

Phase Diagram of Kob-Andersen-Type Binary Lennard-Jones Mixtures

“…The eutectic of these two crystal phases is located around 26% B particles, but interestingly there is a narrow region around the eutectic in which the bipyramidal orthorhombic PuBr 3 structure is the thermodynamically stable phase. We also studied the Al 2 Cu, Fe 3 C, and Ni 3 P structures shown by Fernández and Harrowell to be of low energy at T = 0 and p = 0 [37], but found that their melting temperatures are all lower, compare Fig. 3 and Table I.…”