title: Attraction-driven aggregation of dipolar particles in an external magnetic field.
abstract: We present a detailed experimental study of the aggregation of particles of permanent magnetic moment in an external magnetic field. The experiments are performed with millimeter-sized particles floating on the surface of water. Due to the large size of the particles, thermal noise does not have any relevance in the system; the particles undergo deterministic motion. Experiments are carried out varying the concentration which also controls the relative importance of the dipole-external field and the dipole-dipole interactions. We determined the exponents characterizing the aggregation process and found that the attraction driven aggregation of dipolar particles obeys the Vicsek-Family dynamic scaling. The exponents are found to have a concentration dependence which can be attributed to the change of mobility of clusters and their interaction at higher concentrations.
authors.affiliation: Department of Theoretical Physics, University of Debrecen, Debrecen, Hungary.
authors.forename: Gergo
authors.initials: G
authors.lastname: Pál
authors.forename: Ferenc
authors.initials: F
authors.lastname: Kun
authors.forename: Imre
authors.initials: I
authors.lastname: Varga
authors.forename: Dóra
authors.initials: D
authors.lastname: Sohler
authors.forename: Gang
authors.initials: G
authors.lastname: Sun