Capacitance changes in ferronematic liquid crystals induced by low magnetic fields

The response in capacitance to low external magnetic fields (up to 0.1 T) of suspensions of spherical magnetic nanoparticles, single-wall carbon nanotubes (SWCNT), SWCNT functionalized with carboxyl group (SWCNT-COOH), and SWCNT functionalized with Fe3O4 nanoparticles in a nematic liquid crystal has been studied experimentally. The volume concentration of nanoparticles was phi(1) = 10(-4) and phi(2) = 10(-3). Independent of the type and the volume concentration of the nanoparticles, a linear response to low magnetic fields (far below the magnetic Freederiksz transition threshold) has been observed, which is not present in the undoped nematic. DOI: 10.1103/PhysRevE.87.014501