Three-lobe-shaped equilibrium states in magnetic liquid bridges

Stable 3-lobed cross sectional equilibrium shapes, invariant under rotations of 120 degrees, are reported in magnetic liquid drops confined between two horizontal plates in the presence of a vertical dc magnetic field. Their connectivity with other 4-, 3- or 2-lobed shapes as magnetic field strength varies is studied experimentally. Although 3-lobed shapes are found to evolve into bent 2-lobed ones by slowly decreasing the field strength, the reverse transition is not observed when the field strength increases. Moreover, 2-lobed shapes suffer a bending transition, by increasing the field strength, which is found to be hysteretic.