Direct observation of magnetic ordering in the (CH3NH2)K3C60 fulleride.

The zero-field muon-spin-relaxation (ZF-micro(+)SR) technique provides direct observation of the development of antiferromagnetic long range order in the hyperexpanded methylaminated fulleride salt, (CH(3)NH(2))K(3)C(60) below T(N) approximately 10 K-coherent ordering of the electronic magnetic moments leads to a local field of approximately 25 G at the muon site at 1.2 K.

Methylaminated potassium fulleride, (CH3NH2)K3C60: towards hyperexpanded fulleride lattices.

Co-intercalation of methylamine molecules into the cubic K3C60 lattice affords the fulleride (CH3NH2)K3C60, which was characterized by Raman and MAS 13C and 1H NMR spectroscopy. The high-resolution synchrotron X-ray powder diffraction technique was employed to determine its crystal structure at ambient temperature. We find that CH3NH2 bonds to K+ ions residing in the pseudo-octahedral interstices, thereby providing an efficient and facile route to hyperexpanded close-packed strongly anisotropic fulleride lattices, while retaining the electronic contact between the C603- anions.