Testing the magnetism of polymerized fullerene

Abstract

We present band structure calculations of rhombohedral ${\mathrm{C}}_{60}$ performed in the local-spin-density approximation. Rhombohedral ${\mathrm{C}}_{60}({\mathrm{R}\mathrm{h}\ensuremath{-}\mathrm{C}}_{60})$ is a two-dimensional polymer of ${\mathrm{C}}_{60}$ with trigonal topology. No magnetic solution exists for ${\mathrm{R}\mathrm{h}\ensuremath{-}\mathrm{C}}_{60}$ and energy bands with different spins are found to be identical and not split. The calculated C $2p$ partial density of states is compared to carbon $K$-edge x-ray emission and absorption spectra and shows good agreement. It is concluded that the rhombohedral distortion of ${\mathrm{C}}_{60}$ itself cannot induce magnetic ordering in the molecular carbon. The result of magnetization measurements performed on the same ${\mathrm{R}\mathrm{h}\ensuremath{-}\mathrm{C}}_{60}$ sample corroborates this conclusion.