Statics of magnetic bead chain in magnetic field

Experimental, numerical, and theoretical investigations have been carried out on statics of a magnetic bead chain in the magnetic field. Chains formed on a solenoid coil were observed and chain lengths and slant angles were measured by a digital microscope. It was deduced that (1) the chain length depends on both the surface loading of magnetic particles and the magnetic flux density, and is almost independent of the particle diameter if the sufficient amount of particles are provided; (2) chains incline in the inclined magnetic field and the inclination of the chain is enlarged by the gravitational force. These configurations of chains are approximately determined to minimize the total potential energy that consisted of the gravitational and magnetic potential energy. These characteristics were qualitatively confirmed by the numerical calculation with the two-dimensional Distinct Element Method. The investigation is expected to be utilized for the improvement of the two-component magnetic brush development system in electrophotography.