Magnetic properties of carbon phases synthesized using high   pressure-high temperature treatment
  Two sets of samples were synthesized at 3.5 GPa near the point of C60 cage collapse at different annealing times. A clear structural transformation from mixture of C60 polymeric phases to graphite-like hard carbon phase was confirmed by X-ray diffraction and Raman spectroscopy. Magnetic force microscopy and superconducting quantum interference device were used to characterize the magnetic properties of the synthesized samples. We found that the sample preparation conditions used in this study are not suitable to produce bulk magnetic carbon. 
K.-H. Han, A. Talyzin, A. Dzwilewski, T. L. Makarova, R. Hohne, P.   Esquinazi, D. Spemann, and L. S. Dubrovinsky