Ground state structures in ferrofluid monolayers

Computer and theoretical investigation of particle arrangements in a thin film of a magnetic fluid at low temperatures is presented. The approach developed by us combines the simplicity of simulations and accuracy of the analytical model and allows studying particle aggregates and their properties. The systems under investigation were: a monodisperse and a bidisperse model in the absence of an external magnetic field, and a monodisperse model under the influence of an external field. Careful analysis of the most probable microstructures in a ferrofluid thin layer has been carried out at 0 K. The analysis of the stability of structures under thermal fluctuations allows making a conclusion about the microstructure of investigated system at low temperatures.

Research highlights
► Analysis of the most probable microstructures in a ferrofluid thin layer has been carried out at 0 K and at low temperatures.
► We found ground state for a monodisperse and a bidisperse model in the absence of an external magnetic field, and a monodisperse model under the influence of an external field.
► Analytical expressions were obtained for the total energy of these ground state structures.
► We compared our theoretical predictions to the results of simulated annealing and found them to be in a nice agreement.