title: Coarsening scenarios in unstable crystal growth.
abstract: Crystal surfaces may undergo thermodynamical as well as kinetic, out-of-equilibrium instabilities. We consider the case of mound and pyramid formation, a common phenomenon in crystal growth and a long-standing problem in the field of pattern formation and coarsening dynamics. We are finally able to attack the problem analytically and get rigorous results. Three dynamical scenarios are possible: perpetual coarsening, interrupted coarsening, and no coarsening. In the perpetual coarsening scenario, mound size increases in time as L~t(n), where the coarsening exponent is n=1/3 when faceting occurs, otherwise n=1/4.
authors.affiliation: Dipartimento di Fisica e Astronomia, Università di Firenze, Sesto Fiorentino, Italy. sofia.biagi@ujf-grenoble.fr
authors.forename: Sofia
authors.initials: S
authors.lastname: Biagi
authors.forename: Chaouqi
authors.initials: C
authors.lastname: Misbah
authors.forename: Paolo
authors.initials: P
authors.lastname: Politi