Alignments magnetically forced

Actually, the only forces between spin are magnetic forces which are exceedingly small and the only reason that spin figures in the answer is that the constraints imposed by the Pauli principle correlate different spin alignments with different electrostatic exchange energies. Thus spin is only an indicator...", J. H. Van Vleck and A. Sherman, Rev. Mod. Phys. 

A magnetic field exerts a force on each of the two poles of a dipole (particle), forcing it to align itself with the hnes of magnetic force. 

This magnetizing field will in turn induce the magnetic moments (what that means is discussed later) in the material to align themselves either with or against the applied field. It can be shown that the magnetic force on a material with magnetization M and volume V is given by ... 

Fig. 11.8 Schematic representation of LC PMPs after magnetically forced alignment. The a discotic lamellar (Dl) structure of Poly-2 and the b hexagonal columnar (Colh) structure of Poly-3 at room temperature. Reprinted with permission from [13]. Copyright 2009, Elsevier...

K. Suda, J. Yoshida, S. Nimori, K. Akagi, Hierarchical stractures of self-assembled helical conjugated polymers - magnetically forced alignment of liquid crystalline poly(meto-phenylene) derivatives. Synth. Met. 159, 943-948 (2009)... 

J. Oguma, R. Kawamoto, H. Goto, K. Itoh, K. Akagi, Magnetically forced alignment of liquid crystalline aromatic conjugated polymers and their electrical and optical anisotropies. Synth. Met. 119, 537-538 (2001)... 

K. Akagi, H. Goto, H. Shirakawa, T. Nishizawa, K. Masuda, Fused state C-NMR study on liquid crystaUine polyacetylene derivatives - magnetically forced alignment and orientational behavior, Synth. Met., 69, 33-34 (1995). 

Figure 14 shows schematically both spontaneous and magnetically forced alignment of side-chain liquid crystalline conjugated polymers the former and the latter generate multidomain and monodomain of liquid crystalline phases, respectively. 

FIGURE Iti Schematic representation of magnetically forced alignment of the side chain liquid crystalline mono-substituted polyacetylene and sample cell for the four-probe method of electrical conductivity measurement. 

FIGURE 19 Polarizing micrographs of Fe-based PPCH803A polymer (a) fan-shaped texture with no external force (b) aligned with magnetic force held of 0.7 Tesla where magnetic held is parallel to the horizontal direction. 

Recently, studies of stabilized LC alignment obtained by using polymer networks have been reported. A photocurable monomer is added to the LC, and it is polymerized by UV exposure after the LC has been aligned either by the surface method or by usii electric or magnetic forces. An application for an PTiC was reported based on this approach, and good alignment of the FLC was reported [31]. 

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