Alignment of Anisotropic Particles by Magnetic Field as Seen by NMR

We applied 13C and 205Tl NMR for studying alignment of particles of graphene and high temperature superconductor (Tl0.5Pb0.5)(Ba0.2Sr0.8)2Ca2Cu3Oy caused by magnetic field. These compounds have layered structure and reveal anisotropic magnetic susceptibility. We found that the field of 8 T causes minor alignment of powder graphene and somewhat better alignment of fluffy graphene particles. Herewith the effect of alignment is well pronounced in 205Tl spectra of the superconducting particles fixed in epoxy in the field of 8 T. This effect is reflected in the 205Tl line shape measured in a magnetic field of 1.17 T and becomes much more pronounced in measurements made in high magnetic field of 8 T. Spectra simulations allow determining the degree of the particles’ alignment.