Ferromagnetic nanoparticles suspensions in twisted nematic

• A study of magnetic nanoparticles insertion in planar and twisted nematic cell was performed.
• A decrease of the Freedericksz transition threshold was observed in twisted cells.
• A theoretical model to explain decrease of Freedericksz transition threshold was developed.

Ferromagnetic nanoparticles insertions in nematic liquid crystals (NLC) in twisted configuration are studied and a theoretical model is proposed to explain the results. Experimental observation revealed that nanoparticles tend to overcrowd in long strings parallel to the rubbing direction of the alignment substrate of the LC cell. Their behavior under external field was studied and their interaction with their nematic host is described using elastic continuum theory.