Optical Methods for Studying Aggregates Formed in Magnetic Fluids Based on Solvents with Organic Additives

In this paper we consider two optical approaches to investigate large aggregates of nanoparticles in magnetic fluids. We used diffraction of focused radiation on a stabilized object to determine aggregate thickness. The registration of birefringence caused by the appearance of an anisotropic structure arising under the action of a magnetic field by polarization-optical method was used to study aggregation process. As a result, we detected aggregates formed in media with organic additives, with a significantly increased size.