Sm(TTA)(3)Phen domains in a ring pattern were assembled by the Langmuir-Blodgett (LB) film technique. The domain pattern was observed by Brewster angle microscopy (BAM) at air/liquid interface and by atomic force microscopy (AFM) on mica, Under the electrostatic forces, Sm(TTA)(3)Phen molecules move towards and nucleate at the edge of the stearic acid (SA) domains exhibiting gradient electric field, resulting in the formation of ring domains of the samarium complex.