Strong orientational coupling in two-component suspensions of rod-like nanoparticles

Abstract

We consider two-component suspensions of non-magnetic and magnetic rods and show that alignment of the magnetic component by a magnetic field orients the non-magnetic one. We studied suspensions of non-magnetic V2O5 rods doped with magnetic Fe3O4 nanoparticles. In the isotropic phase, the field-induced orientation of Fe3O4 particle chains aligns the V2O5 rods. Moreover, the nematic phase reorients towards the field at ≈50 Oe, much less than the ≈5 kOe needed for pure V2O5 suspensions. Such effects should exist in any suspension of two kinds of rods, one of which is sensitive to an external field.