title: Long-time dynamics of the directional solidification of rodlike eutectics.
abstract: We report long-duration real-time observations of the dynamics of hexagonal (rodlike) directional-solidification patterns in bulk samples of a transparent eutectic alloy. A slight forward curvature of the isotherms induces a slow dilatation of the growth pattern at constant solidification rate and triggers the rod-splitting instability. At long times, the rod-splitting frequency exactly balances the dilatation driven by the curved isotherms. The growth pattern is then disordered and nonstationary but has a sharply selected mean spacing. Well-ordered growth patterns can be grown using time-dependent solidification rates.
authors.affiliation: Institut des Nanosciences de Paris, CNRS UMR 7588, Université Pierre-et-Marie-Curie, Campus Boucicaut, 140 rue de Lourmel, 75015 Paris, France.
authors.forename: Mikaël
authors.initials: M
authors.lastname: Perrut
authors.forename: Silvère
authors.initials: S
authors.lastname: Akamatsu
authors.forename: Sabine
authors.initials: S
authors.lastname: Bottin-Rousseau
authors.forename: Gabriel
authors.initials: G
authors.lastname: Faivre