Crystallization in glassy suspensions of hard ellipsoids

Abstract

We have carried out computer simulations of overcompressed suspensions of hard monodisperse ellipsoids and observed their crystallization dynamics. The system was compressed very rapidly in order to reach the regime of slow, glass-like dynamics. We find that, although particle dynamics become sub-diffusive and the intermediate scattering function clearly develops a shoulder, crystallization proceeds via the usual scenario: nucleation and growth for small supersaturations, spinodal decomposition for large supersaturations. In particular, we compared the mobility of the particles in the regions where crystallization set in with the mobility in the rest of the system. We did not find any signature in the dynamics of the melt that pointed towards the imminent crystallization events.

Influence of Molecular Shape on Solid-State Packing in Disordered PC61BM and PC71BM Fullerenes

“…On the other hand, the ODF for PC 61 BM reveals a single peak at 90°, a feature that is also indicative of ellipsoidal packing; as noted above, functionalization of (perfectly) spherical C 60 molecules renders the substituted fullerene as an ellipsoid (aspect ratio of 1.19 if the methano-bridge carbon atom is taken into account). Viewing PC 71 BM through the same lens (now with an axial aspect ratio of 1.33) suggests that if the PC 71 BM molecules were perfect ellipsoids, they should pack densely with significant long-range order; ,,,− however, the presence of the phenyl–butyric acid–methyl ester group renders PC 71 BM an imperfect ellipsoid with reduced packing ability.…”