The filling of carbon nanotubes with magnetoelectric Cr2O3

Abstract We report the encapsulation of the antiferromagnetic and magnetoelectric oxide Cr 2 O 3 inside both multi - and single-walled carbon nanotubes. This is achieved by a two step post-synthesis filling process which involves the filling of nanotubes with CrO 3 either from aqueous solution or from the molten phase, followed by appropriate annealing sequences. TEM imaging confirms significant filling rates for both multi- and single-walled carbon nanotubes. Analytical transmission electron microscopy implies that after secondary annealing Cr 2 O 3 is formed inside the nanotubes.