Anisotropic self-diffusion in ferrofluids studied via Brownian dynamics simulations -: art. no. 031504

The anisotropic self-diffusion in ferrofluids in the presence of a magnetic field is studied by Brownian dynamics simulations. It is found that the diffusion parallel to the magnetic field is hindered when compared to the case without field. Depending on the strength of dipolar interactions, the diffusion perpendicular to the applied field is either enhanced or hindered due to the field. The average diffusion coefficient is found to decrease with increasing concentration and dipolar interaction strength, but to be independent of the magnetic field strength for moderate dipolar interactions. Comparison to mean-field models show agreement for moderate dipolar interaction strengths but significant deviations in the regime of strong dipolar interactions.