Data and scripts from: Phase diagram and aggregation dynamics of a monolayer of paramagnetic colloids
We have developed a tunable colloidal system and a corresponding theoretical model for studying the phase behavior of particles assembling under the influence of long-range magnetic interactions. A monolayer of paramagnetic particles is subjected to a spatially uniform magnetic field with a static perpendicular component and a rapidly rotating in-plane component. The sign and strength of the interactions vary with the tilt angle theta of the rotating magnetic field. For a purely in-plane field, theta = 90 degrees, interactions are attractive and the experimental results agree well with both equilibrium and out-of-equilibrium predictions based on a two-body interaction model. For tilt angles 50 degrees ≲ theta ≲ 55 degrees, the two-body interaction gives a short-range attractive and long-range repulsive (SALR) interaction, which predicts the formation of equilibrium microphases. In experiments, however, a different type of assembly is observed. Inclusion of three-body (and higher-order) terms in the model does not resolve the discrepancy. We further characterize the anomalous regime by measuring the time-dependent cluster size distribution. The data files in this collection are associated with the paper "Phase diagram and aggregation dynamics of a monolayer of paramagnetic colloids", An T. Pham, Yuan Zhuang, Paige Detwiler, Joshua E. S. Socolar, Patrick Charbonneau, Benjamin B. Yellen, Phys. Rev. E, (2017). They include .txt and .m files with associated raw data and generating scripts to allow for replication of the figures.
