The dynamics of the Soret effect in thin film of magnetic fluid

The Soret effect in interference field of two intensive laser beams in the thin film of magnetic fluid was used to create a periodical structure of de nsity of magnetic particles. The structures obtained were indicated using t he self-diffraction of the optical beam creating the structures. The relaxa tion phenomena after switching off the laser interference field were discus sed in terms of the spectrum of relaxation times. This spectrum is proporti onal to hydrodynamic particle size distribution. The relaxation of optical grating consists of two well-defined channels, i.e. decay through single pa rticles and small aggregates, respectively.