Ferromagnetic nematic liquid crystals

This review presents experimental realization and behaviour of the ferromagnetic nematic phase, which is observed in different suspensions of magnetic nanoplatelets. After a general introduction, the challenges in the synthesis of magnetic nanoplatelets and preparation of the nematic suspensions are discussed. A brief explanation of a simple macroscopic theory, which can be used to understand the main features of the ferromagnetic phase, follows. In the main part, four different ferromagnetic nematic systems are presented: (i) ferromagnetic suspensions of the platelets in nematic liquid crystals, (ii) dense suspensions in an isotropic solvent – ferromagnetic ferrofluids, (iii) biaxial ferromagnetic nematic suspensions, and (iv) chiral ferromagnetic suspensions. The main focus is on the formation of the ferromagnetic phases and the growth of the magnetic domains. At the end, dynamics of ferromagnetic liquid crystals and methods for their observation are briefly discussed.