language: en

Two-Dimensional Melting of a Crystal of Ferrofluid Spikes

François Boyer 1 and Eric Falcon 2
1 IUSTI, Université de Provence, CNRS (UMR 6595),
5 rue E. Fermi, 13 453 Marseille, France
2 Laboratoire Matière et Systèmes Complexes (MSC), Université Paris Diderot, CNRS (UMR 7057)
10 rue A. Domon & L. Duquet, 75 013 Paris, France
(Dated: September 18, 2009)

We report the observation of the transition from an ordered solid-like phase to a disordered liquidlike phase of a lattice of spikes on a ferrofluid surface submitted to horizontal sinusoidal vibrations. The melting transition occurs for a critical spike displacement which is experimentally found to follow the Lindemann criterion, for two different lattice topologies (hexagonal and square) and over a wide range of lattice wavelengths. An intermediate hexatic-like phase between the solid and isotropic liquid phases is also observed and characterized by standard correlation functions. This dissipative out-of-equilibrium system exhibits strong similarities with 2D melting in solid-state physics.

PACS numbers: 47.65.Cb, 64.70.D-, 05.70.Ln