Interactions of magnetized dust particles in complex plasmas

Summary form only given, as follows. Recently, multilayer complex plasma structures were studied in an external magnetic field In these experiments, spherical micrometer sized paramagnetic particles are levitated in the sheath region. The levitation increased with the strength of the magnetic field Moreover, some particles attracted each other and formed, elongated structures - grain chains, oriented vertically, parallel to the field lines of the external magnetic field. These features cannot be explained on the basis of pure electrostatic forces. Short-range dipole interactions between magnetized grains have to be invoked. Hence there is a need for a comprehensive treatment of various mutual dust-dust interactions, including the forces due to induced magnetic and electric moments of the grains. Which of the forces prevail is determined not only by the parameters of the dust particles, but is dependent on the discharge plasma conditions and magnitudes of the sheath electric and magnetic fields as well. Here, various mutual dust-dust interactions in complex plasmas, including the forces due to induced magnetic and electric moments of the grains are discussed. It is shown that the dipole short-range forces can be responsible for the formation of the field-aligned chains. Such chains may incorporate a few tens of individual particles, as frequently observed in experiments.