J. Phys. I France 1 (1991) 1263-1277
Stability of two-dimensional packings of disks built with ballistic depositionRémi Jullien1 and Paul Meakin2
1 Bât. 510, Physique des Solides, Université Paris-Sud, Centre d'Orsay, 91405 Orsay, France
2 Central Research and Development Departement, E.I. du Pont de Nemours and Company, Wilmington, DE 19880-0356, U.S.A.
(Received 6 March 1991, accepted in final form 23 April 1991)
Two-dimensional packings of identical hard disks of unit diameter are generated using a ballistic model with complete restructuring and starting from a first row made with disks horizontally regularly spaced by , with ranging from to . The stability with respect to random vertical displacements for the disks in the first row was studied. A transition from a pseudo-regular array without defects to a random structure with defects is observed when the amount of disorder (amplitude of the vertical displacements) passes a critical value and a phase diagram is measured in the plane which can be understood in terms of simple geometrical arguments. The random structure found for does not depend too much on and strongly ressembles to the one obtained when starting from a horizontal basal line: the density of defects decreases as a power law with height and the large-height defect-free structure is characterized by a broad distribution of bond angles.
© Les Editions de Physique 1991