title: Crystallization of hard-sphere glasses.
abstract: We study by molecular dynamics the interplay between arrest and crystallization in hard spheres. For state points in the plane of volume fraction (0.54 <or= varphi <or= 0.63) and polydispersity (0 <or= s <or= 0.085), we delineate states that spontaneously crystallize from those that do not. For noncrystallizing (or precrystallization) samples we find isodiffusivity lines consistent with an ideal glass transition at varphi_{g} approximately 0.585, independent of s. Despite this, for s < 0.05, crystallization occurs at varphi > varphi_{g}. This happens on time scales for which the system is aging, and a diffusive regime in the mean square displacement is not reached; by those criteria, the system is a glass. Hence, contrary to a widespread assumption in the colloid literature, the occurrence of spontaneous crystallization within a bulk amorphous state does not prove that this state was an ergodic fluid rather than a glass.
authors.affiliation: Dipartimento di Fisica and CNR-INFM-SOFT, Universitá di Roma La Sapienza, 00185, Roma, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Zaccarelli
authors.forename: C
authors.initials: C
authors.lastname: Valeriani
authors.forename: E
authors.initials: E
authors.lastname: Sanz
authors.forename: W C K
authors.initials: WC
authors.lastname: Poon
authors.forename: M E
authors.initials: ME
authors.lastname: Cates
authors.forename: P N
authors.initials: PN
authors.lastname: Pusey