Alignment of Anisotropic Particles by Magnetic Field as Seen by NMR

We applied 13 C and 205 Tl NMR for studying alignment of particles of graphene and high temperature superconductor (Tl 0.5 Pb 0.5 )(Ba 0.2 Sr 0.8 ) 2 Ca 2 Cu 3 O y 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 205 Tl spectra of the superconducting particles fixed in epoxy in the field of 8 T. This effect is reflected in the 205 Tl 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.