Magneto-optical granulometry: on the determination of the statistics of   magnetically induced particle chains in concentrated ferrofluids from linear   dichroism experiments
  An analytical theoretical model for the influence of the magnetically induced nanoparticle chaining on the linear dichroism in ferrofluids was developed. The model is based on a statistical theory for magnetic nanoparticle chaining in ferrofluids. Together with appropriate experimental approach and data processing strategy, the model grounds a magneto-optical granulometry method able to determine the magnetic field dependence of the statistics of magnetically induced particle chains in concentrated ferrofluids. 
V. Socoliuc and L.B. Popescu
cond-mat.soft